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MG TD TF 1500 - Wiring my fog & driving lights...

Well,
That is a scary thought, what with lucas smoke and real fire smoke dancing through my leetle brain. Yikes!

But, how does one go about it?

Electrical 101 is advanced material for me so here goes: I have a fog light and a driving light mounted on the bar up front. No wires hanging out. I have a single dash mounted fog light switch as standard with no wire running to the light bar.

I suppose I need to buy some wire: what kind/gauge/supplier?

Switch: Can I run both lights in series from the same switch? Or do I need to add a separate switch?

What else does a dummy need to know?

Octagonally,

DaveL

dave lackey

Dave, my wiring loom has a wire lead hanging down for the fog lights. I just hooked them up and the switch is on the dash. One of the two small black knobed ones. One thing you might consider is do not use the battery to test things. Always use a battery charger.
TOm

Dave,
Wire from the switched side of the dash switch (the lead that isn't always on, but which comes on with the switch) to EACH of the lamps. The other wire from the lamps needs to be connected to a GOOD ground. You might consider running a second wire (consider black) to a clean and tight bolt on the chassis. I would use about 14 gauge stranded wire - better too big than too small. If you don't care about the color, any hardware store should carry it. But first check to see that you don't have a red/yellow (as I recall) wire somewhere in the vicinity of the switch and the front apron.

Cheers,
Lew Palmer
Lew Palmer

Dave,
First thing "fog light and a driving light". OK ..I have the same. Problem here is that if you run the "driving lamp" whislt actually driving in fog your "fog" lamp will be wothless. (kind of like turnning your bright lights on in fog of heavy snow you vision will bw worse!)
IMHO your best "cure" is run 2 new wires to your lamps back to the dash (put an inline fuse in them is not a bad idea!) ...then run those to a pair of toggle switches hidden under the dash...then on to your dash "aux" switch.
Your new toggle switches will now act as a fused "pre-select" allowing you to use either fog / driving or both.
I made a small pannel for some "extra's" I added to my TF and have 4 "pre-select" fused accesories that will now operate from my aux switch on the dash. Mine is actually a little more complex in that I used relays and dual possition switches and can use my fog and driving lamps as fturn signals as well. (this is more "Eletricial 202" and you may not want to get this involved!)
See "Ttalk" and click on the cartoon image of "Izzy" to see pannel and fusing.


If you want to just keep this "101" and are still in the "dark" a bit contact me off line and I can wipp up a quick easy to follow drawing for you to follow that would at least allow you to use fog or driving lamps independently!
dsheward@columbis"dot"rr"dot"com
(take out the "dots" and insert the "."!
Cheers,
David 55 TF1500 #7427
David Sheward

What else does a dummy need to know?

oops ...for me that would be to run spell check or buy a new keyboard ..or learn the differance between a "r" and a "f" and an "e" and a "w" !
David
David Sheward

Good info David. I will be wiring a similar setup (1 front fog, 1 rear fog 'red', and 1 driving lamp. I have an aux panel that has two toggles, and two warning lamps that will be mounted under the dash. Hadn't thought of your suggested method, but it sounds pretty good.

Larry
L Karpman

Dave S. - "or learn the differance between a "r" and a "f" and an "e" and a "w" ". You should try typing responses with your left index finger swathed in gauze. Since I learned to type properly in high school, now when typing with only three fingers on the left hand, I have to use the middle finger to substitute for the index finger. The result of this is that when I try to hit the letter that would normally be hit with the index finger, I always get the letter that is normal for the middle finger. While I am getting better at it, I still spend a lot of time correcting my typing. On the other hand, my wife never learned to type and only sues two fingers on each hand and if one of them is taken out of action, it makes absolutely no difference to her typing (can you imagine 30 years of producing a newsletter using only four fingers to type with?).

The gauze wrapping of my left index finger is to cover the raveges of having gotten the tip of caught between a piece of wood and the ram of a hydraulic log splitter two weeks ago. The two doctors that I have been seeing since doing the dasterly deed keep saying that the finger (minus the top half an inch) looks great and my response is that it looks like hell to me (I guess it depends on which side of the finger one is viewing it from). Cheers - Dave (stubby) DuBois
David DuBois

David D....

YIKES!!!!
dave lackey

To David Db all I can say is "OUCH!!" To David S I can only wonder when Ohio's capital city changed its spelling to Columbis. To Dave L. -- get the scoop from Dave S about installing relays in the wiring. Do not trust the standard panel switch to carry the current of these lamps. 'Stubby' DuBois is also an excellent reference for wiring relays into circuits.
Bud Krueger

Buying new keyboard tomorrow ...this is madding... Adjacent keys are sticking!
half the time I type an "u" I get a "y" and a "i" as well ..it's driving me nuts and if I don't run spell check now it's getting hard to tell what language it is!
Dave D ...ouch!
Columbus is still Columbus ..not "Columbis"
David
David Sheward

Hi,

Yoww!! David D,sorry to hear of your plight.Nasty.Hope all heals well.

David S,I admire your electrical 'tricks' on your TF.
Being a bare 101er,I am fortunate that TD/TFs over here in 'Kangaroo Country' really only need clear lensed Spotlamps-fog is pretty rare!

Dave L,Your enthusiasm is amazing.Do you ever sleep!?

Finally,Happy New Year 2007 to the Daves and all other contributors to this BBS.

Cheers
Rob.Grantham
R GRANTHAM

Dave,

Before you wire up your front auxiliary lamps, stop and think about the load you might put on what is already a puny generator. The early C39PV is rated at a paltry 17 amps at 2,000 RPM, while the later C39PV2 is rated not much better at 19 amps at 2,100 RPM. For purposes of this argument, one must assume a freshly rebuilt generator putting out 13.5 volts at abt. 2,000 RPM.

If one assumes you are using standard 55 watt bulbs in each lamp, that comes out to 3.985 amps. If both auxiliary lamps are on, that requires 7.97 amps. Add your head lamps on low beam at another 7.97 and without any other load, you would require minimally 16.95 amps.

This does not include any allowance for your ignition system, side lamps, instrument lights, tail and brake lights - add a minimum of at least 2 more amps. There is no safety allowance for wiper motors, high beams (60 watts per lamp) And for God’s sake, don’t honk your horn!

You can see that quickly, you are at the rated capacity of your generator, if you chose to run both auxiliary lamps simultaneously.

I think you should wire-in a relay to cut out your regular headlamps when both auxiliary lamps are on. Or install a double throw switch so that only one of the two auxiliary lamps can be operated at any one time. Alternately, and again, using a relay, you can wire your auxiliary lamps to be operable only with the main headlamps in the off condition. This assumes that your auxiliary lamps throw the necessary light to the front and side for safe driving.

Gord Clark
Rockburn, Qué.
Gordon A. Clark

Hi, Gord!
Great food for thought. Now, let's see, I have a C40 generator which puts out what...22 amps? Using 16.95 amps plus instrument lights and taillights would put me where?

Remember, I am E 101 here...surely there has to be a way to have a fully operational TD that can use fog lights and a driving lamp occasionally, such as when I am on tour at night!??? What do I need to do, rig up a second 26R battery just for auxiliary stuff?

Thanks again!

Octagonally,

DaveL
dave lackey

Gordon brings up some good points that appear to be well supported when I look at old photos from the 50's of the cars and how they were "accessorized" if you will.
Many of them appeared to have either a single "fog or driving lamp" in the center or 1 of each. The factory only "gave" us a single wire for our "aux" switch. I have got to wonder that "back in the day" maybe you would get out of the car and "plug in" the lamp you wanted to use dependent on current conditions? (After all our cars came with tools & hand cranks back then ...we weren't as lazy as we are today!)
I live near a lake and get fog quite a bit out here so I actually "use" the fog lamp a good deal of the time ...we also have some fairly curved back roads (full of "Bambi-es") ..so I do run the driving lamp at night as well. Those old Lucas lamps really do a great job of lighting up the road way! (Not just for "show" as on some of the newer cars!) The amber fog on my TF puts the factory fog lamps on my Mits to shame!
I have never tried turning all the accessory lights on at the same time as I am sure the genny would not handle it, but I have, at times had more than one on for a few minutes and have not had problems with that.
Cheers,
David
David Sheward

Dave,

Electrical Wiring 101 is quite simple. The math is simple too. The number of watts, divided by 13.5 volts = amps. If you want to be conservative; watts ÷ 12 volts = amps.

The license plate lamp is 6 watts
The flasher relay takes 18 watts
The ignition system and panel lamps ~ a total of 2.2 watts
Each tail lamp is 6/24 (X2) watts which means that its 6 watts per bulb w/o the brakes applied, and 24 watts with the brakes applied.
Each side lamp is 6/24 watts (X2). Similarly, when flashing, add another 48+18 watts, or 4.9 amps.

If one assumes that you don’t use your brakes, horn or flashers, we need add only another 20.2 watts or 1.5 amps for the ignition system. Without applying your brakes, we’re now up to a total of about 18½ amps. Holding your foot on the brakes, will add another 3.55 amps. And for Pete's sake, don’t use your horn or high beams. That could put you over the capacity of your generator, albeit only for a very short interval. And using your flashers will only compound the problem. A heater is out of the question (uses high amperage)!

As I indicated above, if you limit the use of your auxiliary lights to only one at a time, and make sure your generator and all associated wiring, are in good order, with the C40, you should be OK.

Gord Clark
Rockburn, Qué.
Gordon A. Clark

Thanks, Gord...

Gotta ask the question: What WOULD happen if I used my horn? Or other auxiliaries? Meltdown???? LOL...well, seriously...what would happen?

BTW, where in the world do ya get all those numbers? Cool....


Octagonally grateful,

DaveL
dave lackey

Have two lucas lights on my badge bar, a spot and a wide (lights up both ditches)...I have tripod pl700 lucas bpf headlamps.
On occasional nights I light them all up...and high beams and dash lights... The ammeter goes about 2 amps to the minus. Think that would be good for a couple of hours driving...!!! Have never tooted the horn but think you could probably get away with a few toots before the world exploded.
Electrically speaking, the only thing a TD needs (or should have) are a few more fuses!
gblawson - TD#27667

As Gordon says: "all associated wiring, are in good order" ...that's the biggie!
And ...IMHO....add some extra fusing!
Biggest mistake I see people do all the time : "Hey I'll just go out and get some #10 wire, cause thicker is better and have at it". About 1/2 the people I have helped with their wiring problems this & bad grounds ARE the problem!
I had a neighbor stop by this summer that kept "melting" the wires off his "driving lamp install" ....by now he had installed some #6 wire left over from his son's stereo install and directly to the battery with no fuse! DO NOT BE THIS GUY!
#16...good grounds, relays from the 1/2 amp rated switch he wanted to use & (5amp / ea.lamp)fusing was a much better way to go! (it even "smells" better! LOL)
Davd L. :
Are you a positive (original) or negative (modified) ground car?
Before you do ANYTHING ..disconnect the battery ..that is day 1 first lesson for electric's 101!
David
David Sheward

And I'll add disconnect the ground side because you can't spark anything inadvertently from that side of the battery.

warmly,
dave
Dave Braun

David S,
Where can I get an auxiliary panel for just the driving light and/or fog light? I noticed that Advance Auto Wire has a kit but no panel.

http://www.advanceautowire.com/fogdriving.htm

(hope the link works)

Actually, I have the battery disconnect down pat...<grin> <wink>...
dave lackey

Gordons analysis is very good and points out exactly why the Brits put such a big battery in the 'T' series cars. They knew the dynamo couldn't keep up with all the things you could turn ON, but the battery would get you home. Then you could hook-up your charger or wait until morning and do some real driving and bring the battery back to full charge.

I think in those days it was not common to worry too much about over charging a battery. Just put some more water in each cell and carry on.

It wasn't until the TB that MG put regulators in the cars. Before that there was a switch on the dash to raise and lower the charge rate.

The regulators were arranged to put out rated current at a certain draw from the A1 terminal on the regulator. If the current draw went up the regulator lowered the output voltage to keep the current from becoming excesive.

If we had a way to measure the internal temperature of the dynamo we could get more power out of them under a lot of circumstances. As my old professor of Electrical Engineering used to say "You can run anything you can keep cool". That would require additional wires to be run, additional terminals on the regulator and all-in-all not a practical proposition for the way we use and show our cars. But it is a thought.
Cheers,
Bob
R. K. (Bob) Jeffers

Dave L...

Thats a lot of money for a few feet of wire... You would find that for about $5.00 you would have the same amount...without the block.
A little strip of aluminum polished would make a nice little panel! (You can use most power tools for wood on aluminum).
gblawson - TD#27667

Dave,
The "link" works ...but if you are still a poss ground car I doubt you will find a kit in auto parts store that will work with directions that come with it! $75.00 is nuts to do this!
Most part's stores will have a small panel with a couple of switches (rated for 7.5 amps) and some in-line fuses and some wire though.
David
David Sheward

Dave ,
Threw together a quick drawing of what you need ...can you oen an excel file?
If so contact me off BBS :
dsheward "at" columbus "dot" rr "dot" com
David Sheward

David S:

You have mail!! Just got in and yes, I do excel files,etc. Think I will look thru one of my catalogs for a panel as well.

Thanks!!

DaveL
dave lackey

Dave...send me the size you want and I will cut one out of aluminium... I have a tiny one for my starter switch (An Austin 'push to start' that was on... It is screwed to the back of the dash and hangs down below...I'm increasing the size to add the heater rheostat and a lucas ingnition light to have as an 'on' light for the heater...It will end up about 5" wide by about 1 1/2" deep or so.... Just as easy to make two....!

http://www.niagarabritishcarclub.org/gb/td270.jpg
gblawson - TD#27667

Hey, I like that idea, Gordon...

Been thinkin about using a toggle switch from an MGA on a panel like that. I could wire the fog light through the original fog light switch on the dash. A new toggle switch for the driving light.

And it would be particularly classy with that octagonal shape you have on yours....hmmmm....what else...a relay?


Best regards,

DaveL
dave lackey

You have mail
gblawson - TD#27667

Gordon,
You have mail. I just received the diagram from David Sheward and I have located some toggle switches at NAPA at a decent price.

Will measure them and get back with ya!!!

Thanks again!

DaveL
dave lackey

Did a larger one for mine today... heater switch, light to show heater is on...starter switch.
Now to figure out how to make that ignition light come on with the heater? Not sure exactly where a ground is?

http://gblandco.com/gb/panel.jpg
gblawson - TD#27667

Sweeeeet!

You do good work, Gordon!


Best regards,

DaveL
dave lackey

This thread was discussed between 26/12/2006 and 29/12/2006

MG TD TF 1500 index

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