New Member/ '65 C10 Turn Signal Problem.

[theastronaut]

I've lurked on here awhile before finally joining. The last few years I've restored a '65 C10 long/fleetside. I've got it about finished up but I'm having trouble getting the turn signals to work properly. It has a new turn signal switch in it. The headlights/park lights work properly, and turning them on has no effect on the turnsignal problem.

Here's what its doing:

With the ignition switch ON:

If I turn the left signals on: The front left light flashes but both rear lights flash.

If I turn the right signals on: They work as they should.

When the signal switch is turned off, the rear lights both flash- fronts are off.

If I push the brake pedal (turn signal switch still off), the rear lights quit flashing and the brake lights work normal. Let off the pedal and the rear lights start flashing again.

With the ignition switch OFF:

If I push the brake pedal the brake lights come on as they should, but the flasher relay cycles without any lights flashing. The rear brake lights do slightly dim when the flasher relay is cycling.

I feel like the problem is in the switch or wiring since all the lamps work at one point or another (so they must be getting power and are grounded). I really don't know what to check to see where the problem is though, so any help would be appreciated!


Couple pics of the truck:

[mikie 1954]

I would post this in the electrical forum. there are some very good guys over there, they sure helped me when I had problems like this.ALSO nice truck.

[jocko]

Sweet truck. Many posts on here if you search for them regarding 60-66 turn signal snafus. I'll bet you someone else's truck that it's a bad ground or discontinuity between bulb/contact. Our trucks are somewhat notorious for that. When my stuff went haywire, it took me awhile, but finally traced it to a bad ground on the front turn signal housing. Sometimes wiggling them around while you have the turn signal on (and it's acting up) will help you find the problem area and then address bad grounds and/or contacts. I also wandered around the tuck with a long set of alligator clips and grounded the housings, etc etc. Another common are is in the bulb receptacles - they get replaced over the years for whatever reason and the quality is less than noteworthy - the bulb receptacle problem is usually related to one of the bulb contacts not contacting one of the receptacle contacts. Takes a little looking - and is sometimes related to there not being enough pressure on the bulb into the socket due to a worn housing (in other words, the retention device, or shape of the receptacle that cause the bulb to be retained is worn - allowing the bulb to almost "float" in the receptacle or jiggle around loosely because the compresison spring that causes the bulb to stay in contact with the receptacle contacts is unable to push far enough to keep it all in touch.) I realize that is probably impossible to understand the way I wrote it, but it makes perfect sense to me! Bottom line - check the light housing grounds (especially the front turn signals) and the bulb contact to receptacle contact continuity/integrity. Electrical problems. Yuck.

[blackmopar]

id check the wiring just aft the connector block that mates to the new switch beneath the column - since thats the junction where the flasher wire comes in - maybe some melted or cracked wire insulation causing an interupt or more possible a wire or two in the wrong position at that connector?

[theastronaut]

Thanks for the input guys. I got the problem located today, the contacts in the new switch aren't bent correctly and were touching without the switch being on. Aftermarket parts...

Old with correctly bent contacts:



New with contacts touching:



I'll get the contacts bent back like they should be (the old ones won't fit the new switch) and go from there.

[theastronaut]

Got it back together and everything worked fine except for the horn, I pinched the wire when I bolted the turn signal switch back down. Got to fix that and all will be good. Thanks again for the suggestions!

[Muleman100]

I had the same problem with an after market turn signal switch, exactly as you described. I replaced them with another switch from the same vendor and everything works fine except they don't cancel and have to manually turn them off.