[mach3514v]

I got a 69 cougar convertible recently too, and Im having an electrical
problem. headlights, brakelights, dash lights all work, but when I move the
auto gear selector into drive, 2 or 1, all the lights are killed. I know
its not the nuetral safety switch as i dissconnected that from the shifter.
The cars still runs, but all the lights stop. No blown fuses. The lights
come back on when i put it into park or reverse. Any Ideas?

 

[Todd]

Check you battery and alternator output, check the ground from the block to the frame when it is in gear maybe the shift in drive is different than in reverse. If it is a short remove one fuse at a time to isolate each circuit. Start with the cheap stuff and work up from there.

 

[TallCowboy0614]

I wonder...

Do you have a console in the car? I wonder if it could be that little light that tells ya what gear you're in? Maybe there's a short in the wire or something that only goes to short when you move the shifter back that far?

Just a thought...and barely that, actually...'cause even if that was shorted, I'd think (there's that word again...) it would blow a fuse, and I'm not sure it would carry enough current to suck down the juice from the other lights...

 

[TheRktmn]

The light for the shifter feeds from the engine compartment. When you disconnected the neutral safety switch connector there were 2 single wire connectors in that group of wires . One goes to teh AC clutch and the other is for the light in the shifter. Disconnect from there and see what happens. BTW - the shifter light is on a different circuit than the dash lights. Do you have a wiring diagram?

 

[mach3514v]

The shifter light is also disconnected so I know its not that. Here's another thing that I disocvered...I stuck a screw driver through the hole in the bottom of the shifter and touched a metal tube on top of the tranny (or maybe it was the tranny i touchec (fmx)...And i got sparks when the tranny tubing and shifter base were touching through the screw driver. Sometimes when I shift through the gears manually..there are some sparks between the gear shift pin and the metal arch that locks out reverse. Another thing is that when all the lights are killed...the water temp gauge is pinged on high, but i put it back into reverse or park the lights come back on and the temp gauge reads normal.

I only have a 70 wiring diagram...its not the dame as my 69
:1zhelp:

 

[mach3514v]

Here's the car

 

[gt390xr7]

Make sure your engine is grounded to the chassis. Sound's like your's isn't...

Bruce

 

[TheRktmn]

Yep, sounds like it's got a bad/missing ground so it's going through the shift linkage. That's the easiest thing to check anyway. Run a good ground from block to neg post, see what happens.

There's a couple of wiring diags here: http://www.mercurycougar.net/modules.php?s=&name=Sections&sop=listarticles&secid=2
I may have an extra one at home. I will check tonight.

 

[TallCowboy0614]

OK, now this is wierd...but we're getting somewhere at least.

If it was just the engine ground, the effects wouldn't be so "drastic" or noticable, would they? And if there wasn't SOME ground between the engine and the chassis, the engine wouldn't even RUN, would it?

Seems to me that it's gotta be a hot wire arching from somewhere...if there is a ground (even a weak one) between chassis and engine, I don't think the spark would happen like it is, would it? at minimum, the current would head out the transmission to the rear axle to the springs to the body and back to the battery, wouldn't it?

My point being that I don't think the spark would be there, since there would always be a complete circuit through the misc car parts, and the introduction of the screwdriver shouldn't create a "least resistance" point that suddenly would cause a spark.

*LOL* Now I'm confusing myself.

I betcha there's a shorted wire in the console somewhere. Check the wire that you unplugged from the console shifter indicator light...see if it grounds out when you shift the gear lever.

Somethin's sucking alot of current to affect all the lights and cause a spark...probably more than would go through the console indicator wire without cooking it...and probably more than would course through the engine even if there was no ground strap, dontcha think, youse guys?

Did the lights also dim when you poked the screwdriver down in the works?

 

[gt390xr7]

TC, the battery is grounded to the block, the coil gets B+ thru the ignition switch. So, the engine could run and all the acc's could be dead. That's why the block has to be connected to the frame with a good gauge wire, because all the acc's run from the frame ground, not the block. Time for recess, now go play...lol...

Bruce

 

[72cat]

Does'nt the gearbox have an earth strap to the frame as well, I seem to remember something about that, somewhere, deep in the dark recesses of my slowly fading memory banks.

 

[72cat]

Nice, very nice cougar, BTW, welcome to the forum.

 

[gt390xr7]

72cat, after almost 35 years, who knows....

Bruce

 

[TallCowboy0614]

oh yeah....

Ummmm...nevermind. *LOL*

 

[72cat]

mach3514v, any chance you can e-mail me the 70 wiring diagram, check your private messages for my e-mail address.
Thanks
Dayle

 

[mach3514v]

OK..here's some more Info..

THe battery's negative cable is bolted to a bolt on the aluminum intake manifold, but I didnt find a wire that grounded the block to the chasis...think i need that?

When i stuck the screw driver down the hole to touch the tranny, it doesnt spark when the lights are on and its in park.

When its out of park ( nuetral, driver,1,2) the lights go out and I do get sparks when i stick the screwdriver down to the tranny. And when i do get sparks. THe lights are still out. Sometimes if I jiggle the linkage like crazy, the lights will flicker on and also the shifter pin seems to be sparking at the reverse lock out arch.

 

[mach3514v]

By the way...the console and its wiring are out of the car. Thats eliminated. The nuetral safety switch is still connected to the harness but removed from the shifter so thats eliminated. The auto shifter light has no bulb and the wire is cut so that's eliminated.

 

[TallCowboy0614]

" and the wire is cut "

Hmmmm....errrrrr...no...that's too obvious...*LOL*
you DID seal off the cut wire, right?

 

[mach3514v]

yeah its sealed off..i found it cut when i starting taking things apart

 

[TallCowboy0614]

I'd try (as someone mentioned earlier) even HOLDING a wire between the block and the firewall...betcha it sparks...

Sounds to me like you have a ground in the lighting circuit...I wonder if someone tightened a screw from, say, the stainless metal thingies that clip the carpet to the frame at the side door frame (sheesh...can't remember what those are called at the moment - brain fade - dammit...and I coulda maybe sounded CREDIBLE this time!!)

Anyway, what if one of those screws went through the taillight wire that's routed under there?

Still though, a short that's drawing enough juice to dim the lights SEEMS to me like it would blow a fuse as well...*shrug* Also, I can't figure why the linkage would only complete the circuit when it's in a drive or neutral gear...