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Triumph TR6 - Electric gremlins

There is an old joke, about a pastor telling a Sunday school class a story, and then asking them about it. The punch line is, "Pastor, it sure sounds like a squirrel, but I know the answer is Jesus!" That's kind of how I feel about this question-I think I know the answer, but I'm kind of hoping it's something else.
1971 TR6, mine for a month or so now. It has interesting electric gremlins. For the last week or so, the horn didn't work; tonight it does. The last time I drove it at night, the car lept running when I turned it off because the headlights were on; headlights off, car off. It didn't do that tonight. Usually, my amp meter is pegged to the + at 3000 or so RPMs, but tonight it was in the middle range. Most interestingly, my dash lights, which worked okay last week, didn't work tonight unless they were on, the lights were on AND I stepped on the brakes. It sure sounds like a ______, but I know the answer is to re-do the wiring! Unless Someone can suggest something. Thanks, John.

By the way, this board seems to attract a lot more helpful responses than the other one I have found. I post these things on both and get more info here!

Oh, and just to make me feel better, the wiring under the dash is really messy looking. There is an old 8 track radio that doesn't work and doesn't appear to be hooked up; it's going as soon as I get a blank radio plate or maybe a new radio, I haven't decided. I found several wires last night that went no where-one didn't go anywhere at either end and I just pulled it out.

Hey John. It all sounds like a general loose connection/oxidation problem to me. It's very sporatic - if something were wired wrong it would be that way, period, not changing all the time. Probably as you drive more and more some of the connections are vibrating back together. But still iffy.

Before you rewire, which will solve it, but is a big PITA, start cleaning connections and GROUNDS where you find them. The poor grounds are the likeliest source, and they are under dash and under hood. Take the drivers seat out, have a beer, get a pillow & flashlight, and relax and go from one end of the dash till you can't reach any more. Hey - you'd spend alot more time down there rewiring!!! Plan on at least an hour because of what you may find - there are grounds on each major instrument (thumbnuts) and more. It will start out a bowl of spagetti, but after an hour it won't be!

Brent B

Hi John

Link to Dan Masters sight go to the bottom TR wiring diagrams and print off the wiring diagram for 70-71 and the last page with some explanations. Color codes for the wires are on the bottom of each page. Some wires have a stripe so a brown wire with a blue stripe is NU.

Purchase some Dielectric grease any auto supply to apply to all connections after you clean them. Keeps them from coroding fast again. Buy yourself an auto test light. $10.00 bucks Hook too a ground and touch what should be power. No light check the ground end first. I am not kidding. The fastest way to to test your grounds is to put a light in reverse connect the ground side to positive battery and then with long wire hunt for bad grounds.

I don't know if you have any electronics experience? And I tried to explain this once before without much luck. I can show it in a lab but describing is damn near impossible. For me at least.

Electricity always find the easiest path to ground. God invented Golfers, metal golf clubs and cleats to prevent lightning from damaging trees.:)

Your batteries positive is lightning and negative is the ground. In a car circuit it will try to use the dumb golfer first but if he's sitting in his rubber tired cart it will use the tree?

On your car each device lamp motor or relay has to have a power going in positive + and a power going out or ground that goes back to the - side of battery. If that power can't find its normal way back to the battery because of bad ground connections it will use whatever it can. So if the power can't get back all the way it uses the next best which could be your headlights whatever. Turn on the headlights and now that ground is lost we have the coil? Car will run forever with lights on.

Took a quick look at the 71 wiring and my best guess would be the ground strap on the steering shaft coupling. Look for a braided wire cable 3inches long about halfway down shaft in engine compartment. Goes from one side to the other of fibre coupler. Clean that up first. Soak bolts with a rust penatrent first though. Almost always cause of intermittent horn problem maybe the rest to.

Can almost bet you washed the car or it was a damp night when all works. Water makes even the rustiest connection conduct current.

Sorry to be so detailed. But I hope it helps. I am a 2 fingered hunt and peck typist.

Bill Brayford

Yep, yep. JUST what Bill said.

You've got a ground that's accepting a feedback of positive current.

THAT is making things work screwy. Feedback on the ground side of things is common and not good.

70% of all carburetion problems are electrical and 70% of all electrical problems are a bad ground.

Again, as my late Father said:

" a good mechanical connection ain't necessarily a good electrical connection"
Orval, 1962

Jim Deatsch

Thanks. I will try what Bill suggests first-it sounds easier. And, Bill's explanation is good, based on what I remember from my younger days when I played around with Ham radio for a few years. I really would prefer not spending hours upside down under the dash, so I will try the easier way first.

Hey John

Your just a latent tech. that got sidetracked making a living doing something else from what I read?

Only rule to remember is if the idiot that designed and put this together managed so can I! Fred the gentleman I refer to below agreed with that completely.

From your Ham days heres a bit of info on a fellow that I was proud to consider a very good aquaintance in his latter years. Nope its not named after him but most people around the world think so. I collect some items from the early days of electro-mechanical printer technology and he would try to flog stuff on me from auction sales to offset his radio collecting costs to add to the museum. Added to the ones he invented himself. Wonderful man.

Just remember to start at the battery and work back :)


Bill Brayford

This thread was discussed between 10/09/2003 and 11/09/2003

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