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Discussion Starter #1
When I put on the brake on my 69 convertible with non tilt wheel after about 20 seconds the green (feed) wire on the turn signal cam starts getting hot and after 1 minute it will melt the plastic in the cam at the green wire and lose connection. Then of course I have to replace the cam. Hard to drive and only use the brakes 15 to 20 seconds at a time.
The turn signal switch I have in there now is a new Scott Drake.
I have tried 3 different sequencers and that made no difference.
I unhooked the sequencer and then only the 2 inside brake lights worked of course but the wire and switch still got hot, it just took a little longer.
I ran new wires from a new turn signal switch all the way to the back with a different harness for the back brake lights only for the same thing.
This is driving me crazy. All of the other lights work just fine.
If I bypass the turn signal switch and run a 20 gauge jumper wire directly to the wires going to the brake lights it will get warm after a couple of minutes but never to the melting stage. If I go to a 14 gauge jumper wire the wire never gets hot but the alligator clip will get warm. I have a 69 hard top with a tilt wheel and the turn signal switch and brake lights work fine in it. Green wire has no heat at all.
Any ideas anyone????????
Thank you, Buddy
 

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Kinda sounds like your brake switch is the only thing creating a return path for the power - so I am wondering if you have all the ground connections hooked up/clean/solid etc? Try ohming out your bulb sockets to the body/frame then to various points on the ground/return side of the harness to see if you can find out where your losing it or not making good contact....check all your ground to body points since the factory one sucks, I'd put in a good solid one while your at it.
 

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I had the same problem with a Cougar that belonged to a friend a while back. Turns out the knothead had installed 1357 bulbs in his tail lamps instead of the 1157 lamps it is supposed to have. It would burn out the stop lamp switch in a few minutes.

 

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Discussion Starter #4
Thank you for your replies.
I have olmed all of the sockets and the grounds and they check out fine. When I restored this car I added better grounds than the factory. Also when I ran the second wiring harness I didn't use any of the original. All was seperate including the ground.
I wish I had the wrong bulbs in it or I put them in wrong but they are 1157 and in correct. I also checked the voltage on the 3 wires coming to the trunk and they had the same or better voltage than my other car that has no brake light problems.
They both tested the same on grounds also.
 

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Either a short or something that is pulling way to many amps due to some variable factors...like poor connections/wrong parts/miswired....etc. About all I can say is divide and conquer at this point....it's not blowing the fuse which is a bit curious, so I would look to see that you have the right fuse to start with, then look to see if you can find out where it may be pulling power from a different source somehow....split the harness appart at various points - apply the brake switch - see if it's pulling any amps, and keep working your way down the line.....

I gotta feeling you will find something like a rub-through in the harness inside the column or soemthing - be sure to shake the harness when you are testing it to see if it spikes or anything....

Bad Horn switch/: http://www.mercurycougar.net/forums...Wheel-(Smoking)&highlight=turn+signal+shorted
 

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Discussion Starter #7
I attacked some more. Grounds are good I even ran a wire from the battery and made no difference. The wires don't get hot except where the green wire connects to the turn signal cam where brake lights and turn signals cancel out. It has a 20 amp fuse.
11.94 volts at brake light switch, Turn signal switch connection, and at the pig tail for sequencer in trunk. drops off to 11.85 at bulbs. I can leave the sequencer unhooked and only the 2 inside bulbs will light up and the turn signal switch will not get hot like that. Hook up all six lights and it does. I took the sequencer out of my other car that has no problems and it still did the same thing. The other trunk harness I used came out of a parts car that had working brake lights and I ran the 3wires for the brake lights and turn signals out of new wire across the back of the seats. The turn signal switch is a new scott drake and I don't have it installed in the column yet. I hold it in my hand.
I didn't have this problem until my original turn signal quit last year and I had to buy a new one. I'm starting to think that the turn signal switch is not strong enough to carry the load of 6 bulbs.
But I just guessing now.
 

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Something is pulling a lot of amps though...but not >20, but there are other things on that feed as well....so I am wondering what's downstream of the switch that is pulling that much juice? Is it possible that the switch doesn't have enough resistance (he wonders out loud wondering if it should have any at all)? I'd ohm that one out compared to the old one just for giggles (in all positions), I'm not sure what exactly your looking for other than a huge difference maybe.....I would "assume" there should be little to no resistance there in any position (but maybe there should be IDK)
 

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Was afraid of that, but was hoping for an aaha moment. hmmmm? According too my wire schematic the power feed for the taillights is from the headlight switch terminal 14 (black) to a connector - which then feeds to the trunk harness....there a 2 ground points in the trunk harness, and a couple in the dash harness (one for courtesy lights?...) The power feed to the stop switch is from the ignition switch through a 15A breaker and then into a tie point feeding to the fuse pannel 20A, the other 20A fuse is the feed to the flasher and goes to the assy leading to the turn switch and emergency flasher switch. Plenty of points of failure for sure....

(Also of note - there are different dash harness' depending on standard/XR7)
 

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Discussion Starter #11
I tried new bulbs today but it didn't change the problem.
I'm trying to find a tail light wiring harness (uncut) for a 69 standard to try next but not having much luck yet.
Thank you, Buddy
 

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Discussion Starter #12
Hello everyone,
Found out what the problem is. It is a manfacturing problem with the turn signal switches. The feed wire from the brake light switch (which is green) is attached to the turn signal cam with a rivet. When the rivet is not stamped (or mashed) properly then the connection is loose and a loose connection builds up heat and then the plastic it is mounted in melts until connection is lost. I bought a new turn signal cam which had a loose connection also but I repaired it by setting the cam with the bottom of the rivet on top of my vise then using a center punch on the top side to mash the rivet a little more to achieve the proper tightness. After 2 light hits with a hammer the wire was tight so the wire did not move now. I also checked the other connections and tightened some of them the same way. Soldering would also work but I did not have any low temp solder as regular solder would be to hot. If any of the wires on the flasher are loose solder is the only option that I have found.
I would like to thank everyone for their help. Robert on yahoo groups is the one who saved the day.
I won't buy any of that brand of turn signal switches again.
Buddy
 

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Awesome - any chance you took any pics along the way - could be a huge help to anybody who has similar troubles.....glad you got it!! Those aren't easy prob's to figure out
 

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Thanks for the help Buddy. I did test one of the two bad switches and there wasn't any current going through from the green wire to the rivet where it melted. Since I spliced in an original used cam from an original standard turn signal switch into the reproduction one, it's made it about three weeks without a problem. The repro turn signal switch is made by OE PRO Automotive and they obviously have a problem sice I'm not the only omne experiencing problems.

JAMES
 
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