Crazy Turn signal problem

[travis1027]

Hi we recently acquired an 04 yukon with 116,000
We're having an issue with the turnsignals and it doesn't seem to whats wrong with everyone else's.
When we turn the signals on they work fine until we press the brake pedal then they start blinking super fast. And when we just apply the brakes they turn signals turn on solid. They seem to get worse and more sporadic at nighttime for some odd reason. Also the cruise control doesn't work
For a start theyre all regular bulbs and none of them are burnt out. So far we've replaced the flasher relay and the brake light switch, so far noting seems to be working. Also check the wiring connectors at the rear behind the passenger wheel and all look good. Im at a total loss here on this and any guidance would be great. My next step is checking grounds around the vehicle but I can't imaging its that.
Thanks you

 

[justirv]

Hi we recently acquired an 04 yukon with 116,000
We're having an issue with the turnsignals and it doesn't seem to whats wrong with everyone else's.
When we turn the signals on they work fine until we press the brake pedal then they start blinking super fast. And when we just apply the brakes they turn signals turn on solid. They seem to get worse and more sporadic at nighttime for some odd reason. Also the cruise control doesn't work
For a start theyre all regular bulbs and none of them are burnt out. So far we've replaced the flasher relay and the brake light switch, so far noting seems to be working. Also check the wiring connectors at the rear behind the passenger wheel and all look good. Im at a total loss here on this and any guidance would be great. My next step is checking grounds around the vehicle but I can't imaging its that.
Thanks you

Unless you have a ground issue, I'm guessing that the CC and signal bulb issue are different. My first thought was LEDs as well, so thanks for clarifying that. I think I had a car a long time ago that had similar symptoms if the bulbs were reversed in their socket (?). Maybe pull one bulb at a time, test, to see of the symptoms are consistent. And asking if the relay you changed out was in the driver's footwell for confirmation.

 

[Tonyv__]

Hi we recently acquired an 04 yukon with 116,000
We're having an issue with the turnsignals and it doesn't seem to whats wrong with everyone else's.
When we turn the signals on they work fine until we press the brake pedal then they start blinking super fast. And when we just apply the brakes they turn signals turn on solid. They seem to get worse and more sporadic at nighttime for some odd reason. Also the cruise control doesn't work
For a start theyre all regular bulbs and none of them are burnt out. So far we've replaced the flasher relay and the brake light switch, so far noting seems to be working. Also check the wiring connectors at the rear behind the passenger wheel and all look good. Im at a total loss here on this and any guidance would be great. My next step is checking grounds around the vehicle but I can't imaging its that.
Thanks you

I had an s10 that was pretty sporadic like you’re describing. It was a broken ground by the rear tail light harness.

 

[travis1027]

Thank you guys for the quick reply, I actually found the issue and was about to reply for anyone else that had this issue lol
It was a bad ground behind the rear drivers side wheel to the frame mount to the body, where you have a ground off the fuel cap goes too! Its completely off!

 

[SpareParts]

Crusty! Good job on the fix.

 

[Doubeleive]

I would say the lights are the least of the problem.... yikes

 

[Tonyv__]

I would say the lights are the least of the problem.... yikes

Don’t know where OP is located…. But that’s normal for us in PA

 

[Doubeleive]

Don’t know where OP is located…. But that’s normal for us in PA

lol, I would probably break that if I drove it.

 

[OBSandaNNBS]

I would say the lights are the least of the problem.... yikes

Don’t know where OP is located…. But that’s normal for us in PA

Yeah looks GOOD to me.

 

[travis1027]

Don’t know where OP is located…. But that’s normal for us in PA

We live in IL just outside the suburbs of Chi, aka the salt belt and they SALT THE HELL outta the roads there's no chevy from the 00's thats escaped this fate around here lol