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MG MGA - Dipswitch and Feet--Rigt Hand Drive

There is just no way I can get my not-too-big left foot ( size 10 attached to a 6ft 2in bod ) on the standard dipswitch without a third joint in my leg . I have special slim canvas shoes for driving but still it is a total pain. I have decided to go for a dipswitch on the dash in place of the unused fog light switch and plan to use a switch I have just bought off Hudsons in Uk (See pic )..looks a lot like the 'flash to pass' switch referenced by Barney and made by Lucas and fitted to some originals. In the above position and with its stalk you can operate by finger from the steering wheel. They also make a similar spring on/off I am considering for a 'flash to pass' switch and putting it in the location of the demist switch on the dash heater panel..again it can be reached with afinger from the wheel.
Would appreciate comments on the problem and my proposed solution or other solutions.
Do I need a relay with the 'flash to pass' circuit or can I just wire from power around the dipswitch to head light wire?

neil ferguson

Neil-
Nice switch, but surely you aren't going to use it to switch full headlamp power? If you drive enough in the dark that the dipswitch is a problem, then you ought to fit relays. With relays it is very easy to use a switch like you have for dipping, and any momentary contact switch for flashing - you're just supplying the main relays with an alternate control power source.
You can alternatively wire the main relays such that they always have control power, but are activated by ground switching. That gives less wires to the control switches and you could use a single center off spring loaded switch for both dipping and flashing in conjunction with the VW dipping relay below.

What I do if there are not relays fitted:
A final useful relay is a VW type headlight dipping relay. This does not turn power on/off, but switches
FR Millmore

FRM...thanks for such a detailed response and I am attracted to the idea of the relay and single wire to switch approach. I am however reluctant to complicate the wiring with relays if not necessary and the original wiring ( and as per my car ) does not have relays ..or even fuses.... in the light circuits as far as I can see and have had no problems with any burnouts of switches or wires and I have had the car for 20 years( very dry driving conditons over here in Oz a well ) The new dimmer/dipper switch I propose is rated at 10amps and I was going to wire in parallel with the existing dimmer/dipper unit .
Am I being naive??
neil ferguson

I have the same problem as you Neil, maybe worse as I wear size 12 shoes UK and if I wear running shoes or trainers in the MGA I sometimes get the shoe jammed between the pedals when changing gear or using the dipswitch.

I have also looked at fitting a dipswitch on the dash but not yet found anything that will look right on the dashboard and as the car isnt driven very often at night, the job is on my "to do eventually" list.

Your switch looks like it is the"2 way" type so that it can switch from dip to mainbeam A simple on- off switch would only operate EITHER dip or mainbeam but NOT both.

If you have halogen headlights fitted at approx 60watts, your switch will have to carry 10 amps on mainbeam so it probably asking too much of it to be working at its maximum capacity for any length of time.
My advice would be to go with the relay method, then the switch would be very lightly loaded and much safer.
You will need 2 relays, one for each circuit and therefore 2 switching wires.
Your separate "flash to pass" switch is wired to the mainbeam relay.
I would mount the relays at the front of the car near the headlights and take the opportunity to put a fuse into the main power feed for them. Make sure you use a large diameter wire for the power feed and you will most likely find that the headlights are brighter than before as the original wire can restrict the amount of current to the lights.
Barneys MGAGURU website carries lots of info on this and there are numerous threads on the subject in the archives of this forum.
best of luck and let us know how it goes.
colyn
colyn firth

Neil-
We discussed all this at some considerably length recently, under the thread "Relays and fuses" or somesuch, and continued in "Extra fuses re-think and re-work.", both from Lindsay Samford. I finally gave up arguing with people.

You can easily fit the VW dipping relay, right where the current dipswitch wires are, with no modification of wiring other than running the single ground lead to a momentary contact switch or pushbutton.

That said, I am a firm believer in relays and fuses, and I have the test results to show why. They can be fitted with only minimal wiring mods and none to the main harness. And when you are done you will be able to see!

A 10A switch is on the ragged edge with any pair of reasonably modern lamps, especially for constant switching service, which will fry the contacts. Your very pretty switch is better for switching a pair of relays. Whether the lamps are halogen or not makes absolutely NO difference, despite the constant repetition that halogens use more current. Modern standard bulbs use 55/60W - H4, sealed beam, or other. That is at nominal design voltage of 12.8V at the filament; if your system is working really well (14.0-14.5V at the lamp), the current will be noticeably in excess of 5A per 60W filament

FRM
FR Millmore

Your enthusiasm and quoted current levels have convinced me -off to get relays. Many thanks.
neil ferguson

Neil-
If you want more than you can stand, email me and ask for Electrobabble.

FRM
FR Millmore

FRM
You are right that halogen lamps do not need more current than standard ones, they are just brighter.
I was working out ampage using Ohms law (Watts= Volts * Amps) and an assumed 12 volts to calculate the current needed to run two 60watt main beam headlights and to show that the switch was not really rated high enough for the task. I also kind of assumed that everyone was using halogen headlamps nowadays rather than the original tungston filament type slightly lower wattage bulbs. (55w?)

I just changed my lamps from replica tripod units to a more modern mgb fitted with halogen bulbs, the difference is amazing. The tripod replicas were so bad that I couldnt really tell if the lights were on main or dip , the light kind of sprayed everywhere. The new units are far better and make night driving a much better experience.
I just need to remember to wear some slimmer shoes to help me get to the dipswitch more easilly.
Let me know how the project goes Neil
Colyn
colyn firth

Colyn-
Some people insist that halogen lamps are no better, but do use more current if they are. Bulbs have migrated upward. Long ago, T series era, they were on the order of 24/36, by MGA time 40/50 was standard, but 55/60 is the current norm, and the specified H4 standard limit.
In the US at least we have some 55/65, because the lamp design is so bad that the extra 5W is supposed to make up for the bad optics - it doesn't work. The replica things are all over the place - you are finding out what US lamps have been like forever. Real Lucas PL were excellent, and I had some with the first available H4 bulbs - superb. I am running H4 in some original Lucas P700 MC lamps, also excellent, but I've heard that the replicas of those are also horrid. Good E code lamps, like Cibie, are astonishing, given proper voltage delivered to the filaments. Certainly two 7" E codes are sufficient for speeds well over 100mph at night. I have no info on UK or Aussie lights, but assume them to be equivalent to E codes, at least from good manufacturers.

FRM
FR Millmore

I put Bosch H4 units with H4 bulbs in my car when I converted from RH to LHD, and can remember well being amazed at the difference between the previous Lucas sealed beam units and the new setup.

One thing that I have noticed is that the Bosch units have now acquired a milky finish which affects the output. Is there a way of removing this or is it just better to replace the glass / reflector unit ?

dominic clancy

Dominic -
By "milky finish" are you referring to cloudiness on the reflector and/or inside of the lens?
This is caused by moisture, and possible other contaminants drawn in as the lamp "breathes" when it heats and cools.
The only true "sealed beams" are the US style monolithic blown glass and vacuum evacuated bulbs. I don't think there was ever one made with decent optics, but they do stay clear, which was the original design criterion.
The Brits refer to "sealed beams" but as near as I can tell this is a reference to the fact that the lens and reflector are glued together (until the glue fails). Early lamps had loose lenses and reflectors with gaskets. That at least keeps people from touching the reflector, which corrodes it; but, it also makes it difficult to clean. This type might better be called "semi sealed" and sometimes is so referred to; it is what virtually all modern lamps are.

If the clouding is only moisture, it can be handled by drying the lamp with the bulb removed, but steps need to be taken to prevent it happening constantly. There is a lot of fiddling with boots and vents to deal with this problem. Cibie seems best at it, and Cibie vented boots (available separately) can usually be fitted to other makes of lamp. The lamps tend to be self drying as they get warm, but they do breathe dust in. I've taken to gluing air filter foam in the vent channels of Cibie boots, or in self cut channels in other (Hella) boots.
Do not try to "seal" a lamp - it can't be done, since there are pressure changes as it heats and cools, which breaks the seal. Some US lamps, like Ford 9004 in Taurus, try this - the pressure breaks the seal, then the lamps first get cloudy, then fill up with water, which can't get out since it's "sealed". The water sloshes around and hits the hot bulbs and kills it. I drilled drain holes in mine. US Mazda use the same wretched 9004 lamps, but have an elaborate flow through double vent and do not cloud or get wet.

Venting of lamps is somewhat affected by the mounting. Our cars with discrete and containing headlamp buckets have somewhat different qualities than moderns with open back mountings. Early Lucas like MGA had "dust excluders" fitted under the headlamp rim. I think these should be left off, since when water inevitably gets into the bucket, it has a very hard time getting out. That means the lamp is breathing from a constantly wet environment.

Cleaning is tricky, but can sometimes be done successfully. You need to use only fluid - nothing as a swab etc, since it will scratch the mirror polish of the reflector. You can use a swab on the inside of the lens, especially if it's a glass lens. I've had friends clean lamps with distilled water and isopropyl alcohol, shaken vigorously and rinsed with same. Then dry with a hair dryer, set up so that there is free exhaust out of the lamp as you blow in with the dryer; ie, some baffle arrangement. I've thought of using a weak solution of dishwasher machine detergent and distilled water, since it has antispotting agents, but I haven't done this.

Cautions: The reflector is vapour deposited aluminum, so nothing caustic, and it's very delicate - DO NOT TOUCH!. Moisture or even high humidity for extended periods without clamping pressure (from the headlamp mounting) weakens the glue on some lamps, and the lens falls off! So dry it out, and store them dry. I've glued some back together, but getting the orientation correct and finding a good glue is fun - you do get a chance to clean things though!

FRM
FR Millmore

FRM

I can assure you that what we Brits call "sealed beams" are just the same as the American version - a sort of very large bulb with two filaments and a three prong connector out of the back.

I know what you mean by the combined reflector/lens with a separate bulb but have never heard of a generic name for it.


Malcolm
Malcolm Asquith

Dominic, Milky deposit is probably dust deposited on the inside - probably can be removed by careful use of a brush with a solvent like meths on it - but as FRM says - be careful not to touch the reflector. I have tried this with the Lucas spot lights with mixed results.
FRM - from memory our UK sealed beam units made by Lucas were the large vacuuum "bulbs" you describe but I have not used one for about 30 years when they were fitted to my 1971 Mark4 midget and 1972 Morris Marina Coupe ( yes I'll admit to having one but it did get us to the south of France without breaking down!)
cheers Cam
Cam Cunningham

I have very large feet - and unfortunately, wide feet as well. After reading this, I now plan to put the dip switch up on the dash with a relay, etc. I had already planned to put headlight relays and fuses in, so I'll just have to figure out all the wiring when I finally get that far.
AJ Mail

Neil, I have to admit that at first I thought that relays were an added complication, but thanks to a bit of encouragement from FRM, I sat down and had a think about it and it really is dead easy to add them to your headlamp circuit. No alteration to your stock wiring harness is required, you just connect the relays to the end of harness where it would normally go directly to you headlights, one relay for dip and one for main. Then run a battery supply, preferably fused, down to the two relay's contacts, the other side of each of the contacts go to their respective headlamp filaments, simple! I mounted the pair of relay sockets (so I can easily replace them if they should go faulty) to the right hand side of the bonnet shut panel so that the harnesses and the RH headlamp feed could easily reach them . The benefit is less current through your light switch and dipswitch and less voltage drop on your headlamp supply. I ended up doing the same on the ignition switch circuit, thus reducing the current through that switch as well. My car now has three extra relays and six additional fuses, every circuit on the car is protected by a fuse, less than a day's work and it required no alteration to the standard wiring harness.
Lindsay.
Lindsay Sampford

Just to reiterate:
If you still are running a generator with the two coil control box, your light power supply feeding the relays should come off the A1 terminal of the control box. 3 coil (bobbin) control boxes and alternator equipped cars it comes off the connection of the battery cable to the starter switch.

FRM
FR Millmore

Gents..I am a mechanical engineer by profession and need clarity in my grey cells before I launch into the electron moving side of the trade.
I attach a basic drawing of the hook up I propose for the system based on comments on the thread and kit I have ..

Switch AA-- from Hudsons UK (part 020.146)...6 terminal ,off-on-on, 50 mm long stalk,12v,10 amp---to be used in place of existing light dash mounted light switch..ie no lights--sidelights/dash--- power to switch BB.

Switch BB--from Hudsons UK ( part 020.144)...3 terminal,on-on,50mm stalk,12v,15amp..to be used to flip betwen dip and head via relays as below and in place of existing and unused fog lights switch. Good for finger access from wheel

Switch CC...fom Hudsons UK (Part 020.145)...sprung off/on..new headlight flasher switch function, 12v, 10amp.To be placed in empty dash hole ( demist ) on heater panel. Good finger access fom wheel

2 pcs relays...fom local auto shop, rated 12v,30amp and with built in 30 amp fuse...for power to dip and head.

Before I leap in advice from you guys who understand the electrons please..?
....Is layout OK?
....Where to put the relays to minimise wiring changes?
....What wiring rating should be used for lights( or is existing OK)??
....Any other comments?

Get this mod done and the jammed left foot syndrome should end..and I can start making friendly signals to truckies...

neil ferguson

Well, basically OK and will work, but a little off.

Switch AA-- from Hudsons UK (part 020.146)...6 terminal ,off-on-on, 50 mm long stalk,12v,10 amp---to be used in place of existing light dash mounted light switch..ie no lights--sidelights/dash--- power to switch BB."
>>>This is the same as the OE light switch, no need to replace.

Switch BB--from Hudsons UK ( part 020.144)...3 terminal,on-on,50mm stalk,12v,15amp..to be used to flip betwen dip and head via relays as below and in place of existing and unused fog lights switch. Good for finger access from wheel
>>>correct, BUT you use the three wires now connected to the foot mounted dipswitch for this. Just extend them to reach BB. It will only be carrying relay control power, like 0.1A or less.

Switch CC...fom Hudsons UK (Part 020.145)...sprung off/on..new headlight flasher switch function, 12v, 10amp.To be placed in empty dash hole ( demist ) on heater panel. Good finger access fom wheel
>>>OK. Run a jumper feed from 'power in' at OE switch or AA to this; and a jumper to the High beam side of BB. The HB will flash if lights are "OFF", or 'ON low". You could get fancy and run the out side to both high and low control output at BB, but you need to put diodes in both CC out leads to prevent power backfeeding from one to the other. This will flash both H & L simultaneously with lights 'OFF", and will light whichever beam is not on when one beam IS on.

2 pcs relays...fom local auto shop, rated 12v,30amp and with built in 30 amp fuse...for power to dip and head.
>>>The point of fuses is to protect the wiring, so fuses should be at the power source. In this case that means at the regulator, assuming you have standard gen/reg system. The relays should be located as and where Lindsay said, both for efficiency and ease of wiring, so your fuses are at the wrong end of the feed wire. You can do it if you are very careful about protecting the feed wires as they go from regulator to relay, but I prefer in-line blade fuses at the power take off over the relay mounted ones.

Before I leap in advice from you guys who understand the electrons please..?
....Is layout OK?
>>>As stated
....Where to put the relays to minimise wiring changes?
>>>As Lindsay says
....What wiring rating should be used for lights( or is existing OK)??
>>>14 ga US, or 28 strand by old Lucas. The OE wiring is now only carrying the very small control current, up to the relays.
....Any other comments?
>>> the pigtails from relays to headlamps should also be replaced with 14Ga, including the ground (earth)= Black legs, if you want max benefit from all this. This is optional, but at the very least all connections should be clean and protected with OxGard or similar. There should be additional earth points to the car at the front where the relays are mounted, makes a lot of difference.

FRM
FR Millmore

I wear size 13 shoes and have owned MGA's for over 35 years.Barefooting is the only way to go for me!
HCR Rathvon

FRM..got all of that and appreciate the detailed advice ...
I understand therfore that there is only one long distance heavy wire to run..to the two relays at the front of car and the rest is local stuff...I note your advice re good earth connections...
..and I have an alternator on the car so should I put the fuse ( what size..30 amp sounds too much ?) near A1 on the control box?

and HCR...presume after driving around barefoot in winter in Penn that you have lost most of your toes from frostbight so left foot fits well...for me it is like putting my foot in a beartrap ( also proper side drive cars..rt hand...seem to have a lot less space for the hoof!)
Neil

neil ferguson

Neil-
I like to run two power wires, with separate fuses, up to the relays. One is OK, it just looses some redundancy if a fuse blows. 20A fuse should be adequate, I've never had one blow.
If you have an alternator, take power off the start switch where the battery cable attaches. The A1 connection is only for two bobbin regulators.
If you use the relays you have with the fuses built in, run lower amp fuses in them than the primary fuse at power takeoff; ie, 20A to 30A at take off, 15A at relay. That covers double loading if you have low beams on and hold the 'flash' function for a while, tryin' to see them roos!

FRM
FR Millmore

Nice one Neil! I have always driven my mga in a manner that encourages the adrenalin to flow but knowing that my left foot could at any second be semi-severed by a beartrap puts that to a whole new level!!
(Dont think I will ever risk dipping the lights or changing gear ever again!!)
Great post Neil.
Colyn
PS Didnt know there were any bears in Ozz, Did you really mean a "Dingo-trap?"
colyn firth

Hi Neil, here is a picture that shows the position I chose for the headlamp relays.

Lindsay Sampford

....and another picture that shows the fuse panel (cover removed; I have used glass fuses for quaintness!) that supplies the power for the headlamps (and the ignition power), you will notice it is right up close to the regulator to keep the un-fused wiring as short as possible, and that power is derived from the A1 terminal as FRM mentions. My car is running a dynamo converted to -ve earth. Please excuse the scruffy conditions under my bonnet!

Lindsay Sampford

Neil, - By your diagram, if you use flash to pass when driving on low beams you will have high and low beams on at the same time. A single power supply wire would then carry 20 amps momentarily, and it would definitely need at least 25 amp fuse.

If you use a double throw relay for high bean, you can use the Normally Closed contact to supply power to the low bean relay. Then using flash to pass would kill power to low beam when high beam is actuated. Power supply wire then carries only 10 amps, can use a 15 amp fuse, and can be a smaller wire.

Alternate is to use two separate power supply wires, each with a 15 amp fuse (or fused relays).
Barney Gaylord

Barney's correct on the momentary fuse situation, though it probably would not blow if you really used it momentarily. But there's no reason to cut it close, use a 30A. And for the same reasons, this single power feed wire would ideally be upsized to 12ga.

Your 4 terminal relays will be marked:
30 - power in = fused power from batt.
87 - power out Normally Open = to lamps
(the best relay for headlamps has a double 87, for separate output leads to each lamp)
86 - Control + = from existing headlamp wires in harness
85 - Control - = earth
(wires for 85 & 86 can be swapped, unless the relay is diode protected, should be shown on relay)
5 terminal "changeover" relay that Barney mentions adds 87a , Normally Closed

FRM
FR Millmore

Guys ..rabid with enthusiasm I started the wiring last night and the spot for the relays is exactly as per Lindsays recommendation. I have run twin 4mm ( rated 15 amp) wires from the starter switch ( I have an alternator )..each fused 15 amp at source ....one for each relay .
I see your relays have shrouded terminals ...Lindsay..mine are exposed ..and I think I may upgrade as the position may be exposed to a little wet weather at times. I also like Barneys idea re the double throw relay and will look for one ...
Thanks for all the advice.

...and Colin..we have a vicious Bear called the Koala....they leap on you and piss!!
neil ferguson

Neil-
With two separate feeds there is no point to using the double throw or changeover relay.
Lindsay wired his with relay sockets, very nice way, since if a relay fails you just plug in a new one, even in the dark and rain, or KB attacks!

FRM
FR Millmore

Interesting that so many people with such "small" feet :-) have trouble with the dip switch. I wear US size 13, and I'm forever catching the edge of the brake pedal when my foot is on the accellerator. Must be the difference betweek LHD and RHD cars.
David Breneman

The layout in rhd 1600 is tight with the switch high and it cannot be moved lower as there is a body hump underneath. When I look at pics of lhd layout there seems to be much more room for the hoof.
neil ferguson

Finlly finished and tested the new light switch and relay arrangement for dips and head ..plus a new headlight flasher. Used the advice of Barney,Lyndsay and FRM--many thanks!!
Attach a pic of the arrangement on the dash and all switches can be reached by fingers from the steering wheel.
Starting from top left
---the 3 position main light stalk switch replacing the awkward old pull,pull and twist clunker switch.
- --to the right of above ad in the fog light panel hole the dip/head stalk switch replacing the old dipper located in the bear trap (I actually left the old switch and wiring in place and working and used the fog light wire to take the signal from the new switch to the relay-all in paralel with old switch....)..so the slim foot brigade can enjoy the traditional!!
---Underneath and on the heater panel I have used the unused demist location for the spring return headlight flasher stalk switch. (Need to black out the text on the panel.)
All works well..and lights seem a bit more powerful after eliminating most wire voltage losses.


neil ferguson

Glad it works ok Neil, and pleased to see that you have left the original "beartrap" in place for those occasions when you feel like living dangerously!!
Like I said, I will probably do the same job on my car when I run out of more urgent jobs to do.

I couldnt help but notice that you have used the "pull to increase demist" location for the flasher switch which puzzled me for a second.
Then I realised that there are likely to besome subtle climate differences between Victoria Australia and the UK. (probably 20 degrees C !!!)
Up here in the north of England I must use the demist pull control 50% of the time both to clear the screen and de-ice the eyelashes!

So I will have to think of somewhere else to fit the flasher switch.
My thinking is to put the flasher switch in the standard indicator light position which is in fingertip range of the wheel, relocate the indicator light to the instrument dimmer control position and find somewhere convenient under the dashboard for the dimmer control.(I dont really want to drill any extra holes)
My car has a Moto-lita steering wheel fitted which obscures the standard indicator light and so repositioning it that I could see it through the steering wheel spokes would definitely be an improvement. I dont often adjust the instrument illumination anyway and so moving it somewhere under the dash would be no loss.

Will let you all know how it works out when I tackle it over the winter, I had better pre warn James at Bob Wests to have ANOTHER relacement loom waiting for me after the fire!
( I think I must have pyrromaniac tendencies)
Colyn
colyn firth

Colyn..you are exactly right about the demist control..I only just installed a heater unit and control panel a few weeks ago ( most MGAs in Australia never had them )and it was for the airflow only..I did not plumb in the water or fit demister tubes/controls.The problem here is more likely to be roast feet than iced eyebrows!!
Re your configuration another approach would be moving the light switch to the dash dimmer location and then having the dip/head and flash stalk switches next to each other to the left of the wheel....good luck...
neil ferguson

This thread was discussed between 04/11/2009 and 14/11/2009

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