First thank-you in advance for your advice<O

I have an 03 F-350SD with the 7.3 4X4 Auto trans<O</O

The Directional Relay (flasher) ford part #F65B-13350-AA constantly buzzes I
replaced the relay and it still buzzes. The buzzing will stop if you apply the brakes
turn signal or emergency flashers. The bulbs are all good and all work. I took the brake light switch apart the contacts all look good, no burning on the contacts.

Any suggestions.

 

Do you have a brake box or other tow accessories that could be causing the problem? Do you have a voltmeter by chance? We could do a little testing with it.

 

I think I figured it out I beleave it is the combo switch I pulled it out and played around with it whil still connected to the wireing harness I can get it to stop buzzing for a short period of time but it will return if i wiggle the switch or tap on it so it looks like the switch is the problem.

 

I think you are talking about the multi-function switch(turnsignal switch)? If so, that is a very common problem with the 1990's trucks. We will have to wait and see if the 2000 up trucks start having a lot of problems like yours.

 

I found a replacement at rockauto.com for $49.79