A friend of mine drives an 02 f250, and when he's driving the blinker flasher under the dash makes a loud buzzing noise, but it quits when he uses his blinkers or hits his breaks. he went to the ford house and got a new flasher, but it didn't stop. everything works fine, just the buzzing is driving him up the wall. just wondering if you guys could know where the problem might be.

 

sounds like a short in the wiring

 

yupp short somewhere

 

well what the hell is makin it buzz? and short was my first thought too, but how do you find a short thats not blowin any fuses or bulbs, it dosent even burn out the flasher relay? ohm out the plug in? and for that matter how would u ohm that?

 

does this happen when his lights are on, could be a filament has fallen on the light and is back feeding

 

Pull the fuses one by one till the buzz goes away to find the circuit it is on.I beleive that truck has left/right turn sig fuses plus a trailer fuse.Check your trailer plug as they tend to corrod and backfeed the system.unplug it if you can to start.Any aftermarket remote starts or anything of that kind will usually put to much resistants on the systems also.

 

well he dosent have anything aftermarket on it, its gonna be fun checking all the fuses. start under the hood or the dash?

 

I would start under the hood at your turn signal fuses to try an isolate it side to side.LOOK at the trailer plug first if he has one,disconnect if possible.Check for green buildup in any lighting or turn signal connections you can find,pull them apart to inspect terminals not just outer shell.Good luck and let me know