I have had a buzzing coming from under the dash when I would shut the truck down in max A/C. Buzzing would disappear if you turned on the four ways -(dont ask). Dash would vibrate under the radio when the buzzng was happening so I pulled the upper dash and radio out to find the buzzing coming from a group of three relays with a cover over them. Is this the Gem Module? Anyway pulled the big blue relay and buzzing stopped. By pulling the relay I also lost my turnsignals. Anyway to Ohm this thing? I have an ohmeter. Ford only item or autozone?

I have written on the relay part #F65B-13350-AA

thanks

 

The GEM is over the fuse panel, There is a relay block there in the 200 & 2001 one of the relays is the fuel pump

 

I have a 1999.5. Going to go take a pic now.

 

thats the turn signal flasher/relay and its ford only

 

Here is the pic. Blue relay is the one that was buzzin. They group of rlays is not exactly under the radio but a little closer to the driver.

 

The flasher is for your turnsignals and hazards, the reason its buzzing is the harness attached to the turnsignal arm is a factory screw up. From what ive read and had the same exact problem as you, the wires that go from the arm to the flasher are a little short, so any pulling or pushing of these wires under the colum cover and fuse cover causes a spiratic short. If you go to the dealer they will replace this harness and maybe the arm im not sure if it has a plug.
I was able to quiet mine by pushing and pulling slightly on both ends of the harness, it acts up from time to time but i hasnt been bad enough to replace since the initial outbreak. Your problem is not the flasher, its the control arm

 

well, it turned out to be a flasher. Replaced with new and n o more buzzing. Cant belie ve it was that simple. I put up with that buzzing for a little over a year. It would only buzz with the ignition off and the **** in mac A/C. I could control the buzz by turning the fan **** to the off position or by turning the four ways on. (Very weird). Anyway, fixed for now. Thanks for all the help. BTW new relay was $18.56.

 

Ya i bought one and it didnt solve my prob but now i have a spare, if it acts up again youll know where to look, im surprised that was it, maybe just moving the wires around under there changing the flasher relay did it. good luck with it i know how annoying it is when it goes nutz trust me