2010 Ranger. Blue relay beneath steering wheel buzzes steadily when driving or parked with no key in ignition. Changed it out and it still buzzes!?! The only thing that stops the buzz is when I apply turn signal, hit brake, or apply hazzard flashing lights. Buzz continues even with no key in the ignition. Also, when I very slightly move the 5-wire connector that's attached to brake petal, the buzzing stops; when I let go it starts again. Tried taping this connector to brake pedal and the buzzing stopped completely, but this totally drained the battery! So to keep it from buzzing all night I simply apply the turn signal (no flashing turn lights results thank heavens). No short circuit on the ground under driver's side seat. Please help with any suggestions!

 

Welcome to the forum

Yes, that's the turn signal/4-way flasher relay, the blue one

There are two fuses in the cab fuse box that power the flasher
Fuse 17 is for the 4-ways, hot all the time
Fuse 20 is for the turn signals, hot only with key on

You can pull one and see if buzzing stops if not put it back and pull the other
Since it buzzes with key off I would think its a 4-way issue, fuse 17

Your problem is most likely in the turn signal stalk(called the multi-function switch), also has 4-way hazard switch
So you will need to remove the clam shell steering column covers to get to the switch and its plug ins, then either replace it or see if you can find the problem in the switch

That wire harness you are pulling on goes to the turn signal switch

 

No more buzzing! I didn't remove the multi function switch as it looked so solidly intact and I was afraid I'd ruin something. I just pushed the wires around a tiny bit and the buzzing stopped! Back to normal now. Thanks again!

 

OK, good stuff

Thanks for the follow post

 

I'm having the same problem with my 2010 Ranger. Did you have to remove the clam shell steering column covers? Wondering if that is a difficult job? Is that the main cover over the airbag?