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MG MGB Technical - Headlamp worries

It has come to my attention that last week more than a few people had some headlamp problems. Some had only low beams others higbeams.

In my case only the high beams worked but if I pulled back on the stalk slightly ('69 B), the low beams worked. It was kind of inconvenient to have to drive this way so I shot some contact cleaner which took the problem away.......temporarily. Its back. I will need to dismantle the stalk/switch and clean the contacts manually late this week (and I hope not to do too much night driving meanwhile), but this is my question...

The stalk switch is an aftermarket repro from one of our vendors. Worked fine for three years but got soaked a few times in the rain. Could this be the problem or.....

I also installed high powered halogen headlights recently (6 mo. ago? but not used much at night 'til recent). Could the headlights be drawing too much power therefor burning out the switch contacts?

If Pual Hunt is out there I know I read something about putting the headlights on a relay to help with the extra load on the switch. Could Paul or some other BBS guru give me a hint on how to hook up such a relay? A wiring diagram would help greatly, as well as which relay to use.

Thanks for any replys.

Luis in the Sunny South
Luis

Pauls website

www.mgb-stuff.org.uk

will have all that you need about wiring diagrams, relay fitment etc....

Im fitting relays this week and got all that i need from a couple of threads on this and MGOC webpage and also from hunting around in pauls 'spanner' section on his webpage - tis very useful.

Relays are standard 4 blade type, with or without fuse (your choice) and can be bought practically anywhere i would have though Bought mine from www.vehicle-wiring-products.co.uk but somewhere in US would be just as good.

Electrical burning is quite distinctive and you would or at least should smell the cable sheath burning - it is possibility if you have high powered halogens and no relay (my switch has been burnt which i assume happened after PO fitted halogen sealed beams.

Im hoping fitting relays will also consequently brighten up the rear lights of my car which are pretty dismal too. I understand this may happen due to the headlamps now working off a different circuit with own power feed, creating a lesser voltage drop over the main circuit for car.

~PHIL
Phil

Thanks, Phil. I'll check out the site (and put a bookmark on it for future referance).

To help you out on your tail lights..... I bought a pair of halogen taillights and turn signals from LBC co. (advertises on this site) to help brighten my rear. Helps alot esp. during daylight hours. They were a bit pricey but just plugged right in. With all these amps going through my system I also had to change over to a Bosch alternator at the same time. My lights used to dim when I stopped and my turning signals stopped indicating unless I revved up.

Oh well, good luck and thanks for the lead.
Luis

Luis

Thanks also for the tip!!

I would say though after converting your rear lamps and what else you say too, you really do need a few relays in your system to free up some power!!!!

~PHIL

Phil

OK. Found Pual's site, though nothing on installing relays to headlamps, but.........found a link through his site to Rick Astley's site showing just exactly that....and...... get this......fully colored diagrams. Man, is thid wonderful or what? No need in reinventing the wheel.

Thanks again to Phil and to the wonderful people that made this BBS possible. I would also like to thank the little people....... Yes, the leprechauns and the gremlins in my Lucas wiring for making all these chores on my MG possible.

Luis

Luis - your stalk switch is probably buggered and may have been so by any extra current that the after-market headlamps may be drawing, as well as quite possibly a poorer quality switch than originally. I recently fitted relays and fuses for someone else but would not use fused relays because if the fuse does blow you lose both headlamps, and it will take a bit or presence of mind to flick the stalk or pull on the flasher. I used a separate fuse per filament (i.e. 4) as well as the two relays.

Relays don't 'free up' power, of course, but they do keep it out our expensive switches. In doing so they make the lights brighter, which consumes even more power!

I did see a comparison of incandescent and halogen stop/tail lights somewhere, and the problem with the halogen is that the tails are so bright there is very little difference between them and the stops, meaning that unless someone happens to be looking at the back of your car at the time they may not see them come on. Over-bright tail lights are a nuisance to following drivers, particularly in the rain, which is why it is illegal to use rear fog lights in all but specified situations in the UK.
Paul Hunt

With the new distributor I got loads (pun intended) of power. Hopefully I'll get some time this weekend to rig up the relays and the new switch I just ordered from MOSS, JIK Paul is right.

BTW, the headlights I have came from LBC co. and have a smaller bulb in the assembly to use as daylight running lights. Ain't that peachy. Got'im cheap too (although now that they've seemed to have buggered my $90 switch, not cheap enough.

Paul: I did notice there wasn't much difference in the lights at night, but most of my driving is in daytime anyway. Now if I can rig up a third brake light that only comes on with the brakes.......
Luis

I have been running on one of the recent repro stalk switches for my headlights for some years now. Here are some of my observations on how this whole headlamp, relay, stalk switch system has worked out for me.

First, as Paul says, the relays simply allow us to control the headlamps via much less CURRENT. It is the amperage factor that does the real damage to points, and if we can reduce the amount of amperage flowing thru them, they tend to last longer. In the case of our stalk switches, the contacts were never more than simple brass wiper switch connections in the first place when Lucas made them and are still the same today.

However, my observation is that those made today are often made of something less than identically specified materials and that the assembly and forming of the parts of the switches are sometimes less good than original. NOT necessarily inferior to the task, but like anything done half-assed, it only meets its objective halfway. On my particular repro switch unit, I found that the stamped brass switch contact "arms" were rather indifferently formed and that the "contact patches" on any two pieces of a switch might or might not come together as intended in the original design. I had to do some Tweeking of these little devils with some long and skinny needle nosed pliers to get them to perform as closely as possible to the original manner. This seemed to make their operation reliable and proved that the basic repro switch could function correctly, if it had been build correctly.

I also noted that the material (brass sheet stock it appears in both OE and repro) were somewhat different. The repro material being softer and more prone to burning at the contact points when large amperages were applied. This led me to use relays to reduce the current and lengthen the life of the switch. I did indeed get somewhat brighter light from the headlamps I had (halogens) but more remarkable was that taking the headlight current out of the main harness somehow allowed the current requirements in the remainder of the OE harness to become somewhat more efficient - with the bonus of suddenly brighter dash lighting (tho I had never touched that particular system at all).

So far, I have been lucky with this aftermarket repro as it has been on this daily driver for at least 5 or 6 years now and works just fine - NOW.
Bob Muenchausen

"third brake light" - QED, Luis, just pick up the green/purple and a black in the boot/trunk. If you use the left-hand side for the green/purple you can substitute a double connector for the single that is there.
Paul Hunt

This thread was discussed between 19/08/2002 and 21/08/2002

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