trouble shooting turn signal switch

[Texas63GMC]

I have a 63 and have rewired everything from the cab back, engine compartment and headlights. Most of it is new wire, solid grounds, new bulbs. Headlights, brake lights are working.. I reused the cab wiring after taking it apart, checking for obvious breaks, bad insulation, etc.
BUT, the turn signal is making me crazy. I have read Jolly's web site info. Gone over the wiring diagram, etc.
the LEFT turn signals work, back and front. The turn signal indicator in the dash functions.
However the right turn doesn't work. The bulbs barely flicker. The dash indicator doesn't function. The switch and wiring heat up quickly, to the point of smoking, unless I turn off the ignition.
I have tried several turn signal switches even new ones. (they are for 63 Chevys) the results are the same.
How do I trouble shoot this thing? and please no one say I just need to make 3 left hand turns to go right.........

[AZKen]

The first place to always look is ground.

REAR: Since the turn signal filament is the same as the brake, the rear sockets must be getting good ground. If brake works, then socket it grounded and bulb is good.

FRONT: Since you say right brake light is bright. It could be the front right bulb or the front right bulb socket ground. Switch that bulb with a known good bulb and test the bulb socket for good ground to chassis. While the weak front bulb is flashing, create a temp ground from bulb socket to nearby clean chassis metal. That may brighten the weak flashing bulb(s). WARNING: This can fool you if you do not find a good test ground spot.

No luck with above? Then:
This could be a CONNECTOR. First check all connectors that would be before the front and rear lights. This would be any column connector and the main firewall connector. These connectors have individual contacts. Either blade or round. The connector contacts that are for right turn lights must be intermittent or corroded or broken inside or crimped wire is almost off. To trouble shoot, bypass the connectors at these points. Temporary jumper wire or long temporary replacement wires. You can also tap in at various points with ice pick probe light to detect where weakness starts. Make sure you probe the left first so that you know what your test bulb should look like on a good circuit. You will, of course, need to have key on and turn signal switch clicked to left and right. Your probe light bulb will flash with the front and rear bulbs. An intermittent connection could cause heat. But smoking? Are you sure? From where exactly? Also check flasher unit, try other bulbs, check fuses and wiring AGAIN! Let us know what you discover. It will be a series of clues and a bulb will go off in your head.

[George Bongert]

Originally Posted by Texas63GMC

I have a 63 and have rewired everything from the cab back, engine compartment and headlights. Most of it is new wire, solid grounds, new bulbs. Headlights, brake lights are working.. I reused the cab wiring after taking it apart, checking for obvious breaks, bad insulation, etc.
BUT, the turn signal is making me crazy. I have read Jolly's web site info. Gone over the wiring diagram, etc.
the LEFT turn signals work, back and front. The turn signal indicator in the dash functions.
However the right turn doesn't work. The bulbs barely flicker. The dash indicator doesn't function. The switch and wiring heat up quickly, to the point of smoking, unless I turn off the ignition.
I have tried several turn signal switches even new ones. (they are for 63 Chevys) the results are the same.
How do I trouble shoot this thing? and please no one say I just need to make 3 left hand turns to go right.........

Greetings Texas!

This doesn't sound to me like a bad connection. Heating and smoking of the wire(s) and/or directional switch (especially the new ones) indicates to me that you have an electrical short circuit somewhere. Check to be sure that you don't have a wire with bad or cracked insulation (that you may have missed) somewhere that is allowing a live electrical circuit to come into contact with a metal ground. I would thoroughly check the steering column, since that is a place where wires can become pinched, potentially breaking the insulation and causing a short circuit. None the less, double check everything. Better to be safe than sorry!

[jrmunn]

Texas,

I agree with George. Heat and smoke means the current is too much for the wiring - and will soon ruin it. (If you have ever had a tool touch both battery posts, the melted metal shows how much heat an auto electric system can produce.) If the blinker sounds weak, I would start looking for a short to ground between the switch and the blinker. Beyond this, it could be anywhere along the wires to the weak lights. On my 64, the under dash wiring insulation is getting brittle, and it has even come off one of the wires at a firewall plug - but I have not tried to fix this because it is hard to reach and is still working. I keep thinking that I should get to it while I still can, but there always seems to be something else that needs doing first.

JRMunn

[AZKen]

Make sure the fuse associated with that circuit is not too big or the wiring is not too small. Wiring must be "matched" to fuse size. A short should blow a fuse way before smoke/melt. That's why I asked about the smoke. Like where is it coming from exactly? etc. A fuse should be protecting. It is possible that a component has resistance, not shorted, and is causing heat. Flasher, switch, bad connection. A voltage drop test may help. If a hot exhaust manifold has burnt almost thru a wire, it won't carry the current, but not shorted. A broken wire, same thing, but not shorted. If it was a short it should blow a fuse. That's what fuses are for. Usually those bulbs wouldn't still blink with a shorted wire. I still say bulb or ground issue. Hopefully Tex comes back. He knows what he's doing with trucks. He'll find it.
A person can switch the connections temporarily from right to left to see if the problem follows.

[jrmunn]

Texas,

Lots of rain and mud is keeping me close to the computer today. Ken is right about the fuse (don't know why I didn't think of this, but it helps explain why I struggle with electric problems), so the fuse is a starting point. I am still not convinced that a typical bad grounding connection would cause a circuit to over heat, since this should limit (reduce) current (however, I don't know how the flasher works, so it is possible that grounding or lack of grounding there could be a problem, but wouldn't this affect both right and left turn signals). I have needed to fix bad ground connections at turn signal and brake lights that kept them from working but did not seem to cause any heat to be produced (and kept the turn signal light on and flasher off). If the fuse is right, then I suppose that bad connections ahead of the lights might cause resistance that leads to heating; but in this case, whatever is hot and smoking should be where the problem is. If the fuse is too big (or is running several circuits), then either bad connections and/or a short could be the problem. Finally, since both brake lights and the left turn signals work, is it possible that you have a current leak (partial short?) to ground in the front, right turn signal wire or at the front, right bulb or light socket? In the mean-time, you could try hand signals for right turns - but I doubt that any but older drivers would understand.

JRMunn

[AZKen]

I agree fundamentally. The heat and smoke is an issue that is yet undefined exactly. In a way, It does seem like a short. I'm not sure you can have a partial short, maybe. You can't be partially pregnant, I know that.

I suggest making 3 left turns to go right at night and hand signals in the day.

[Texas63GMC]

thanks for all the responses. I will start pulling the electrical tape off and looking at the cab wiring closer and checking all those things....I'm betting it is a short inside the cab.

The heat in the wiring is right at the turn signal switch, but I haven't checked elsewhere. I might have exaggerated the smoking, but the little bit of that was in an older switch...
I've been tinkering with this thing, for several months, on nice weather weekends. So I forget some of what I've done or not done yet.

in looking at the wiring diagram, does the dash turn signal indicator get power off the front turn signal circuit? Both left and right?

[Texas63GMC]

By the way, here is an example of the general condition of the wiring when I got it....

[AZKen]

The signal to flash comes to the TS switch from the flasher. Then sent by the TS switch to the front and rear turn signal bulbs and also the indicator on the dash. Typically they are right= DBL (dark Blue) and Left is LBL (Light Blue). A wire from the dash indicator bulb runs thru the instrument connector to the firewall bulkhead connector and goes to the same pin as the wire(s) that go to front and rear turn bulbs. I would hope you have an accurate schematic/wiring diagram. Glad to hear you have reassessed the smoke issue/heat issue. I recommend you try what I suggest as far as testing/trouble shooting before you rip into all the wiring/switches. I do not think you have a short. Also, I don't know how you are sensing heat from the switch. It is way buried and isolated. Respectfully, Please be sure your info to us is correct and accurate or it will cause me/us to give false info/diagnosis.

Commentary:
Sometimes when we rewire, we follow what a PO did. A PO who did not know what they were doing. This is bad. Sometimes we think we see that they did something wrong and rewire a section to "fix" it. Sometimes the color coding is gone or has been mixed up. Do not go by colors when fixing an old trucks wiring, go by circuit. Wiring must be done very methodically using a good clear diagram. When using a new harness kit, the colors ARE important.