Electrical Short--Turn Signal to Hazard Flasher

[Crofton]

Just bought a '99 Suburban 73K miles and all of a sudden the turn signal seems to be shorted to the hazard flasher.... when I activate right turn (not left) signal, the hazard flasher seems to get voltage, and the turn signal will not flash (flasher module buzzes once under dash). If the headlights are on and the right turn signal is activated, all the dash lights flash too. Tried a new flasher module, no help. Is there any home diagnostic I can make before I go to dealer and start what could be an expensive witch hunt for the short?

 

I have taken steering column apart on an 84 Vandura, and am not axious to try that surgery again, however. Anything a little more simple for me to try?

 

Also I am wondering what could have caused this. Truck has clean Carfax; cannot tell otherwise if it's been bashed. It worked perfectly when I bought and inspected it, of course.

 

Thanks for any help

Carl in Crofton

[GM-Tech]

I might first suspect something as seemingly innocent as a bulb. Not one that's simply burned out, but a broken filament that's laying across the other filament in the bulb, causing some voltage feedback. Or even a bulb that's internally shorted... very rare but I've seen that happen too.

 

First step, turn on the park lights and walk around the truck and see if all lights, particularly on the right side obviously, appear to be lit normal. Have someone step on the brakes with the park lights both on and off and see what that looks like on the front and rear.

 

If there's a trailer harness of any kind, definitely look there. It could be tucked up, out of sight, so don't assume just because it's not hanging down that it doesn't have a trailer harness. If it has one and it looks aftermarket, try to find out where it's tapped into the lighting circuit. Seen some of those modules that are used with aftermarket trailer harnesses cause a problem. Also seen corrosion in the connector itself cause a short between circuits.

[texan_n_vegas]

I am having a similar problem with my truck. The hazard and turn signal keeps shorting out, no right turn. No back up or brake light. Everytime I turn the hazards on it blows a fuse on the fuse box in and under the hood. I think I pinpointed to the hazard switch or turn signal switch. I need to get to them and was wondering if that was your problem.