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MG Midget and Sprite Technical - column switch, 1978 on GAN6

Hi. My 1500 midget's column switch has failed so I had no high beam lights (that was an interesting moment)! It has the Lucas 33773/SQB197 type which was only fitted in about the last year of production. It seems to be unobtainable now, unless I want to buy 500 from a factory in Taiwan making dubious replicas. Anybody know of any spares sources that still have these switches? I'd prefer to use a NOS original type switch than modify a different type. I have already fitted relays to reduce the load at the switch and preserve whatever switch I eventually fit and currently have the dipswitch bypassed and run through a temporary on/off/on toggle switch so at least the lights work, although the weather has been so foul it hasn't been out in the dark for a fortnight!
Grateful for any info to track one of these switches down. Cheers.
RS Hughes

is there a simple way of telling them apart from the early r/b switch or the late RWA switch?
David Smith

Does the headlamp flash part of the switch work?

If so, you could fit a VW headlamp relay and operate your dip/main and headlamp flash just by pulling the stalk.

With the headlamps switched off, pulling the stalk will flash the headlamps. With the headlamps switched on, pulling the stalk will switch between dip and main.

This is the relay...

http://www.ebay.co.uk/itm/301190889775

and instructions...

http://www.mgcc.co.uk/mga-register/wp-content/uploads/sites/22/2014/05/Dip-Switch-Relay-conversion.pdf
Dave O'Neill 2

Crikey Dave - that's a good idea. I I can't find a NOS switch I'll probably go with this. Thanks.
RS Hughes

Hi,


Have you looked closely at the switc? The contacts can usually be fairly easily cleaned up, especially as you only need it pass the very small current to operate the relay coil.


If all else fails get the older type and swap the stalk over, they're only a push fit in the nylon bit.
That way you can keep the horn push as per oe.





I looked at the link to the MGA site using the beetle relay, but without altering the wiring to the switch it just wouldn't work as a replacement in a late Midget.


The beetle relay uses a pulsed earth to changeover or flash main main beam, the MG column stalk is switching lives.
SR Smith 1

you could always use a second relay to make it switch the earth
mark 1500 on the road Preston Lancs

Thanks - I took out the switch and had a gave it a good coat of looking at. IMO the high beam contacts are too badly fried, but I suppose it may be possible to use bits from another broken switch to repair it. If nothing else, decades of British motorcycle ownership have left me with a fair understanding of how Lucas kit is put together!
Thanks for the helpful advice.
RS Hughes

Or just take the blue wire into the stalk to ground and then use the blue/white as a pulsed earth to the VW relay and rewire the headlamp wiring.


Not as straightforward as the MGA link appears. but that does assume yr happy to fit an additional switch, as per the factory optional flash to pass switch on the MGA.
SR Smith 1

SR

You would need to use the purple and the blue/white to switch the relay on the 'flash' switch.
Dave O'Neill 2

You're right Dave, silly me.


And that makes it more difficult I think, as the horn push button uses that feed. The late cars used single wire horns and a switched live.


Like anything, it can be done with a bit of rewiring and a relay.



The best option has to be get a new switch body and swap the stalks over.
SR Smith 1

Thanks guys - your helpful posts are greatly appreciated. I just won an eBay auction for what seems to be the last one in the world! In the meantime I have looked hard at the suggestions you have made and I'm made up that you tried so hard to help an anonymous stranger. Really - thanks gents.
I will do my best to rebuild the faulty switch and offer it on the board to the next poor sod that suffers the vengeance of the Prince of Darkness. No guarantees of course, but please guys - get the relay kit! 50 milliamps versus 10 amps - you know it makes sense! If you want Lucas switchgear to last all you need to do is make sure it's not doing any work. Simples!
Hope you all have a peaceful and happy Christmas and New Year. Thanks for your help.
RS Hughes

Hiya,

That's what forums like these are all about.


I think folk are very hard on Lucas stuff, in my experience it's just as good as contemporary electrical stuff, and alot better than certain italian manufactured items.



Had a mk 3 golf in last week with no headlamps, 96 car, and that was a dud rocker switch! We have more problems with VW group electrics than all other marques put together.



That switch on your car is nearly 35 years old after all, and who knows what current its passed? So many fit higher wattage headlamps or link in spot lamps over the years and overload circuits.



Happy christmas.


Regards Steve
SR Smith 1

RS Hughs.

glad you got a replacement.

What are you going to do with the old Stork? Or even just the knob at then end of your old stork?

I've lost my knob. Well my '73 rwa has. So if your knob's cheap, with or without a stork on it, I could be very interested. LOL.

Really, not joking.
Lawrence Slater

You're right, Steve. I was a bit hard on Uncle Joe, I guess! That said some of the stuff fitted to 50's motorcycles was pretty nasty. Not only Lucas, Miller as well. And you're right again about some Italian kit. I had endless trouble with electrics on both my 70's Ducatis until I fitted secondhand Japanese parts :-)

The real problem is overloading as you say. In my car a previous owner had uprated the lights and as BMC/BL didn't trouble with relays it was bound to happen sooner or later!

My experience of lighting problems in cars of the 70's (at least those I could afford to drive) is that as often as not it's poor earthing that's the culprit. Either by design or more usually corrosion.

Cheers All.
RS Hughes

BTW Dave Smith - there is one way to tell this switch at a glance. Look at the multiway connector on the end of the wires. So far as I can tell it is the only that is white - all the rest seem to be black. Also it has a horn push which most earlier types didn't. So if you spot one at a jumble or something it's maybe worth a punt as they're rarer than rare stuff.
Happy Days!
Rod.
RS Hughes

Hi Lawrence.
I'm going to try to rebuild it, mate. Then offer it as a going concern to some other poor s++ I reckon with repaired contacts it'll be fine, especially if used with a relay kit.
There's stacks of SH switches on eBay, BTW - just not this type, which is made of unobtainium. I'd guess yours is a 37H8050 without a horn push and the little horn graphic would look a bit silly on RWA. Good luck though; if you try a few small independent garages you'd more than likely get a free knob from the scrap pile. In fact I'm going to see my mate in just such a garage this pm. I'll ask him and get back to you - you never know what a bit of brass neck will get you!
RS Hughes

Hi

I do not know the 1500 column switch, but won't a similar vintage one from other BL models suit, such as from various Triumphs, Allegros, Marinas and Minis?

If so, Qulllier Triumph, Minispares, Robsport, Chic Doig and Rimmer Bros might be worth a try. Differnt part numbers and possible connectors.

Cheers
Mike

M Wood

Hi,


You are right in that most BL cars of the 70's used what the same column switch. The Midget has a very short stalk though compared to Mini's or 1100 for instance. But that can be dealt with.


The multiplug is easily swapped over as well.
SR Smith 1

Rod - thanks; reason I asked is that I have a few old stalk switches here, 2 of them have the push / horn facility but do not have the markings of the 1500 Midgets. Think they are 37H8051. There was a short period around 1970/71 when these switches were factory-fitted, I guess they may be interchangeable with the later one like yours.
Lawrence - if I can remove a knob without breaking it I'll put one in the post.
David Smith

Yup no probs Rod. :).

Cheers David. I'll reimburse the post cost if you do have one. Thanks.
Lawrence Slater

Cheers David. 37H8051 is the securing clamp I believe. The switch itself is 37H8050. It would be interchangeable if you cut off and swapped the multiway connector, which isn't hard to do.

Aaah - 37H8050. They just don't write numbers like that anymore heheee!
RS Hughes

Rod

Is your horn switched live or switched ground?
Dave O'Neill 2

Possible stalks?

http://www.rimmerbros.co.uk/Item--i-GRID006237

Cheers
Mike
M Wood

Whole car is negative earth Dave. Why do you ask? But the drawing shows it switching the live side.
I have a replacement switchset coming, but I really appreciate all the help I've had from everyone.
Incidentally I spotted another SQB197 on eBay for £45 tonight. These are like hen's teeth so somebody might want to check it out. The older Lucas number was 33773 and it's often listed as part number ADU1021 which is not a Lucas number. It might be a Moss Europe stock number???
By the way MGOC spares scheme has a relay kit for the headlights for way less than I found anywhere else. This is the kit I used and it was a doddle to install. Seems good quality to me. The relays are rated for 30A so should last well!
RS Hughes

Rod, apologies, you're correct, I gave the number of the clip. The mention in the parts book of 'with horn contact' threw me - the correct number is BHA4948, for early 1275s.
ADU1021 is the Brtish Leyland part # for your switch. A quick google suggests they've been very short stock or unavailable since at least 2011.
David Smith

Rod

Only the very last Midgets and MGBs had switched live horns, where there was a purple feed to the switch and purple/black to the horn.

Earlier models had a switched ground, where there was a live purple feed to the horns, then a purple/black to the switch before grounding through either the column - for cars with the horn-push on the wheel - or through a black wire from the stalk.

Earlier stalks are therefore not interchangeable with the later models.
Dave O'Neill 2

David thanks for your post. No apology needed - I only updated the part number to protect the innocent from buying the wrong thing.
Spot on about the unavailabilty of this switchset. I didn't know ADU1021 was a BL part number - I kinda assumed it was a suppliers stock code.
BHA4948 is very similar. Almost identical but the loom connector is different. I nearly bought one before i lucked onto the right part, thinking i would just change the connector and Robert's your avuncular relation because my car is a late 1500. As I said before the dead giveaway is the connector. Only the GAN6 200000 on cars had a white plastic plug/socket as far as I know. Earlier ones were black.
Matron is coming round now to collect the wax crayons so I have to say goodnight!
Cheers All!
RS Hughes

Is this it?

http://www.autoelectricalspares.co.uk/lucas-sqb194-column-switch-279-p.asp
M Wood

Any of these of interest for others with same problem?
http://www.minispares.com/product/classic/21A2658.aspx

What side was it fitted?

Thanks
Mike
M Wood

Or


http://www.minispares.com/catalogues/classic/Classic~Mechanical~Parts~Manual/Electrical~and~WashWiper/Indicator~~Wiper~Stalk~Switches.aspx?1~10~92

M Wood

Hi Mike,


The first one is for US spec cars, ie wiper switch on the column, no good for RHD cars.


Of the 2nd lot, some could be made to fit, tho the arm would be too long, the Mini had a huge diameter steering wheel as standard.


The last on is BL standard 80's , and that style was never fitted to any midget.
SR Smith 1

Dave O'Neill - you are spot on. 100% correct. I had totally misread the drawing. The horn switch does indeed switch the neutral through to an earth bond point which is shared with earths from the wiper motor and some instruments and idiot lights. The live feed to the horn comes from the permanent live pole on the starter solenoid. I'm still not up on the letter codes for the insulation colours and got tripped up thinking B was blue when it's black of course.
Good catch Mike, thanks.
Rod
RS Hughes

Problem sorted at long last! First I want to say that I am very grateful that so many good people did their best to help me with the fault - you guys ROCK!

The replacement switchset arrived and was fitted today. Not without some drama though. When I first tried it all was well so I put the plastic covers back and went out for a celebratory burn (or more of a smoulder, really). This is when I discovered that signalling left switched on the high beams! Plus the horn stopped working. Bugger.
So I plugged in the original to the loom and found it worked fine, having cleaned up the contacts in the meantime and reduced the clearances with a bit of judicious bending with small pliers. I suppose the addition of a pair of relays helped by reducing the current at the switchset.

So now I'm back on the original switchset. I don't know what went wrong with the replacement, but when I plugged it back in and tried it voila! It worked great! I guess it must have been something I did when I put the covers back on, but I can't imagine what.

The relay kit I bought came from the MGOC spares scheme and it was easy to fit and an absolute bargain IMO, but I should mention a couple of caveats.

First, there were only half the number of solder-on terminations needed. You need 8 and there were only 4 in the kit.

Second the instruction sheet said to fit it on the right inner wing, next to the main loom. I don't know about earlier Midgets, but mine is a late one (April '78) and the main loom runs down the left inner wing so I fixed the relays there between the coil and the washer tank. Also it says to scrape away the paint to provide an earth bond for the relay primary coils. I didn't do this - I ran a separate earth back to a nice big shiny earth bonding bolt on the bulkhead. If you want to fit this kit to a late Midget this may be relevant to you.

I am still scratching my head at the idea that the headlight circuit as standard is totally unprotected! Not a fuse in it from end to end. Bizarre. But the relay kit includes a fuse, which is nice.

The net outcome is that I now have a spare column switch of a very rare type (Lucas SQB197 or 33773; BL Part No ADU1021) which is working and I did a bell-check with my DMM and can't find anything wrong with it. I'm prepared to offer it to to a member who really needs it for what it owes me. If not I'll keep it in the spares box because these are like hen's teeth.

That's it - cheers guys!
Rod.
RS Hughes

Hi again,


Glad you it sorted at last.


It might be bizarre but hardly any british cars until the 80's has fuses in the headlamp circuits.


Lots acquired fused sidelamps in the late 60's but that was about it.



Some Jaguars, E types and mk 2's for instance, had fuses in the main and dip circuits, but only one. Arguably more dangerous as if the fuse blew because of a fault, both lights go out.


Regards Steve
SR Smith 1

SR - you're right of course. With only one fuse you'd lose the lot if there was a problem. Of course you might lose the lot anyway, depending on the fault, even with no fuses. So now the plan is to install a second fuse so the Hi and Lo beams ae supplied separately.
RS Hughes

The best way if you're going to fuse is 2 dip and 2 main, like a current car.


If there is a problem only one light goes out.
SR Smith 1

Yep I realise that and you're right of course Steve, but for simplicity's sake I'm going to install fuses to each relay. If I lose the high beam I'll still have low beam and if I lose low beams it's two seconds work to swap the connections over to the high beam relay so I'll have the low beams running off the high beam relay. Of course, depending on the fault, it might take that fuse out as well but I'll take the chance. If nothing else it would give me a fair idea of where the problem is! It's a bit of a bugger to get at the wires to the individual lamps, but I might change my mind in the future and fuse them all anyway. For now though I'll stick with fuses to the secondary side of the relays.
Your input very much appreciated though. Cheers!
RS Hughes

This thread was discussed between 20/12/2014 and 06/01/2015

MG Midget and Sprite Technical index

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