Turn Signal Weirdness

[Meathead16]

My turn signals have been acting up for awhile. It started as every now and again and has, of course, grown into almost everytime I use them.

When I use my right turn signal my high beams turn on. If I pull the stalk towards me ever so slightly, the high beams will turn off. Sometimes it takes 2 or 3 "nudges" to get them to stay off, but usually one does the trick. If I pull the stalk completely as if I was doing the "flash to pass" as GM calls it, the high beams turn off. Basically the "flash to pass" feature is working in reverse.

When I use my left turn signal its operation is erratic. It either: acts normally, blinks very slow, will stop blinking all together for a random amount of time, hyperblinks as if a bulb was out, blinks about 40 times per second (literally), does nothing, or any combination of the aforementioned in any random fashion it so desires. I've noticed turning the steering wheel, as well as pressing or releasing the brake peddle affects it's behavior. In random fashion, of course.

I've tried a new multi-function switch, and it actually made the problem more consistent. The "nudge" that used to make the high beams turn off when using the right turn signal no longer works, they just stay on. If I hold the stalk in place just before it clicks into place then the high beams do not come on.

Besides the multi-function switch, what else could cause this? Crossed wires? Bad ground?

Thanks in advance

 

[RST Dana]

How old is the battery?

 

[Meathead16]

~1 year, voltmeter on the dash shows a steady 14 with the truck running. This is the only 'active' electrical gremlin..

 

[Matthew Jeschke]

UPDATE I'M STUPID you got a new Multifunction switch and didn't help. Maybe the diagram will still be of help though. Sounds like you have a wiring issue. You'll need to trace the lines in the diagram below. I'd use a power probe makes quick work of this sort of thing.

OLD POST: This happened with my 2006 Buick Lucerne. I was able to isolate it to the multifunction switch as if I applied pressure the switch in certain positions it would behave correctly. If memory serves right it was almost exactly as you explained. I bought a new multifunction switch and problem was resolved.

That said, best to diagnose with a handheld DMM and or power probe. I think there's a connector for the multifunction switch under the molding for the steering column or the knee bolster.

If yours is same as my 2001 Tahoe... Then looks like need pinout for C201. Having a hard time finding it in FSM. Some of the wiring colors are in the diagram below where you see switches towards bottom.