66_l-36 Electrical ground -smoke- AHHHHH!

[Keith B.]

Team, I really need your best advice on a electrical problem. Just re/re rebuilt my L-36. Everything is back together, two weeks ago I posted that I had the engine going but my main "pink" +coil thru firewall to ignition wired fried. Pulled cluster, tore into harness replaced pink wire only one damaged from ign switch to coil and also pink wire on firewall to starter. Today after hrs of work getting cluster back in ( I had numbered all wires to re-hook up), I turned the Accessory switich to left, lights came on, radio and clock worked, headlights buckets moved, then within 30-45 seconds burning smoke from around wiper motor/ignition shield/firewall/resistior. Burning electrical smell. I imediately uppluged battery and cannot visually see any burnt wires, but I just want to CRY !!!

- I had RE-tightend my cig lighter and it is hooked up correctly.
- I had my wiper SWITCH apart and tested it as per recent Restorer article, as it would turn on and never shut off. This could be an issue??
-I obviously had all the wires off my Starter and believe I have them on correctly. Will dbl check.
-My oil sender metal coil is NOT touching the Ballast Resistor. The smoke was definately coming from firewall side center area, not underneath dash.
HOW DOES ONE FIND A GROUND FAULT !!

PLease, please. Trouble shooting ideas's please, area's to double check. I have had this cluster out 3 times in 10 days, I'm 99% certain all the light bulb sockets and blk ground to top spade over Tach is on correctly.

YOUR BEST ADVICE PLEASE, I WOULD LIKE TO GET SOME IDEAS, MY FATHER IS AN ELECTRICIAN AND WOULD LIKE TO POINT HIM TO SOME AREA'S TO DBL CHECK FIRST. I HAVE A NEW 66 LECTRIC LTD WIRING DIAGRAM also. THANK-YOU....THANK-YOU...THANK-YOU

[William C.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

Typically first place to look is a wire cut by the ignition shielding. Look harder where you say the smoke and you should find damage.

[Frank E.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

If the ignition shielding is on, check to see if it's a 65 or 66 shield. A change they made in 66 was the addition of a mylar insulator over the coil to prevent a dead short to the battery that would fry the pink wire to the starter. A 66 has a mylar/plastic button on the top of the can on the left side.

Good luck....

Frank

[Marco H.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

Keith,
It sure seems your problem is in the engine comp't side of the harness. It sounds like you only have the problem when ign. is on. I would try to disconnect the pink wire from the ballast resistor, keep it away from any ground and have someone turn the Ign. on while you touch the wire to see if it gets warm or hot. If so the problem is between there and the Ign switch. If wire stays cool and no smoke develops, reconnect and remove wire from coil and starter ( should be outboard connection.) Make sure again that the bare ends do not touch any metal and ground out. Hold the pink coil wire while someone again turns the key to Ign." If it gets warm, the issue is between ballast resistor and coil/starter, somewhere in the harness. If the harness is original/old I would inspect the leg down to the starter very closely. I have seen many fried or just about to be fried harensses due to heat exposure from poor installation at the starter. Also the single thin black wire needs to be grounded at the outboard starter bolt. One last thing, make sure that nothing is touching the backside of the ballast resistor.
I hope this helps.
Marco

[Chris W.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

Team, I really need your best advice on a electrical problem. Just re/re rebuilt my L-36. Everything is back together, two weeks ago I posted that I had the engine going but my main "pink" +coil thru firewall to ignition wired fried. Pulled cluster, tore into harness replaced pink wire only one damaged from ign switch to coil and also pink wire on firewall to starter. Today after hrs of work getting cluster back in ( I had numbered all wires to re-hook up), I turned the Accessory switich to left, lights came on, radio and clock worked, headlights buckets moved, then within 30-45 seconds burning smoke from around wiper motor/ignition shield/firewall/resistior. Burning electrical smell. I imediately uppluged battery and cannot visually see any burnt wires, but I just want to CRY !!!

- I had RE-tightend my cig lighter and it is hooked up correctly.
- I had my wiper SWITCH apart and tested it as per recent Restorer article, as it would turn on and never shut off. This could be an issue??
-I obviously had all the wires off my Starter and believe I have them on correctly. Will dbl check.
-My oil sender metal coil is NOT touching the Ballast Resistor. The smoke was definately coming from firewall side center area, not underneath dash.
HOW DOES ONE FIND A GROUND FAULT !!

PLease, please. Trouble shooting ideas's please, area's to double check. I have had this cluster out 3 times in 10 days, I'm 99% certain all the light bulb sockets and blk ground to top spade over Tach is on correctly.

YOUR BEST ADVICE PLEASE, I WOULD LIKE TO GET SOME IDEAS, MY FATHER IS AN ELECTRICIAN AND WOULD LIKE TO POINT HIM TO SOME AREA'S TO DBL CHECK FIRST. I HAVE A NEW 66 LECTRIC LTD WIRING DIAGRAM also. THANK-YOU....THANK-YOU...THANK-YOU

It sounds like it is somewhere in the circuit between the Ignition switch and coil. nad probably between the balast resistor and coil (the Pink Wire).

If originally, the pink wire was burned clear down to the starter solenoid, there is a big chance the problem is in the connection to the solenoid or the solenoid itself.

Try the following and see what happens:

(1) With the ground cable disconnected from the battery, unhook the pink wire at the ballast resistor. (The wire that goes to the Ignition switch)

(2) With the ignition switch in the "ON" position and everything else off in the car (lights, heater, radio etc.) and the doors closed, momentarially touch the ground cable to the ground (neg) post on the battery. There should be esentially no current draw, only what is required for the voltage regulator which is very small.

A large draw (or spark) indicates there is some thing grounding somewhere else in the system (which I do not think is the case). Let us know if this happens.

(3) Now hook up the pink wire at the ballast resistor and repeat step #2.

If now there is a much larger current draw (or a big spark) then you had in step #2, the problem is (A) in the pink wire itself from the ballast resistor to the coil and starter solenoid (grounding some where, Ignition shielding?), (B) the ballast resistor itself (grounded, which I do not think I have ever seen), or (C) the starter solenoid connection for the pink wire (The "R" terminal, small stud furtherest from the engine), or (D) the solenoid itself (internal shorted), or (E) the coil (internally shorted).

You can eliminate the starter solenoid by disconnecting the pink wire to it.

You can eliminate the ballast resistor by disconnecting both wires and temporarially hooking them both together.

You can eliminate the coil by disconnecting the pink wire connection.

It is just a process of isolating the bad circuit and eliminating what it is hooked to it. I think we can almost be 100% certain that the problem is in the pink wire which is the circuit for the ignition system (coil, ballast resistor and starter by-pass circuit) If the Pink wire is not shorted to ground somewhere (ign shielding?) it has to be one of the components it is hooked to.

NOTE, the coil connections should be orentated so they line up across the car (side to side) and not in the for and aft position. This keeps these connections away from the shielding.

I hope this helps with your problem.

keep at it, You will find the problem!

Chris, CWPASADENA

[Keith B.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

Gentlemen: Thank-you very much for all your assistance, just pulled the cluster AGAIN. Stupid, stupid me..... I had the BROWN spade wire attached to the ground spade above the Tach, not the BLACK grd wire. Idiot.

So the brn wire is somewhat melted, I think I will replace it. This is the one wire my number system fell off. I CANNOT LOCATE WHERE THIS SMALLER BRN WIRE GOES. It has a blk tip spade on the end and when facing the cluster it is on the right of center. Just trying to read my enlarged wire diagram to locate a clip somewhere..........any ideas >> ??

Thank-you so much for your time.....keith

[Keith B.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

Guys, as you may know the long brn wire goes to the radio capacitor next to the ignition switch and it is "HOT". I had it pluged into ground at the top above the tach, all my gauges look good except my Water Temp did a 360, so I'm not sure if it is gone too.

Anyway to check a water temp gauge with cluster out of car, I reset it but not sure if its going to work now. What a crazy mistake putting the hot brn wire to ground and the black ground to the capacitor.....

As you know its so friggin difficult to get all the wires back in especially the tach and speedo, trip, and that short oil pressure wire.........

Thanks guys,,,,,,your thoughts....

[Marco H.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

Keith,
I believe a single brown wire goes to a capacitor that is mounted by the oil press. gauge. (On radio equipped cars.) Check U69 in your AIM.
Marco

[Marco H.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

I guess you got it.

[Marco H.]

Re: 66_l-36 Electrical ground -smoke- AHHHHH!

Keith, leave the cluster installed!!
There are 2 wires at the temp gauge: pink = ign hot, and green = to temp. sender on intake. Remove the green wire at the sender and turn on ignition. The temp reading should be cold (needle to the left.) Now touch the intake with the green wire (ground it out) and you should see the needle go to hot. You don't have to do this for too long. Just to see if the gauge is alive or not. I hope this helps.
Marco