Hello, Have a 1988 Ford F150 with no Brake Lights or Hazard Lights.

-All turn signals working, tailights working.
-Have 12V at Both Brake Switch and Hazard Flasher unit.
-Brake switch checks good.
-Changed Flasher unit.
-Thought it was definitely Multifuncton switch, but changed that and still no go.

Using Haynes wiring diagram, but wondering if something was left out. Was in the harnesses today, but no luck. Looks like same wiring for Brake or Turn, Bulbs OK. Anything else common to both circuits?

This one has me stumped. Thanks

 

My Haynes for 1997 thru 2002 shows electronic flasher controls hazard and turn signals. If the turn signals work, then the hazard has to work unless the hazard switch is bad or the electronic flasher is bad.

My manual shows that if you have voltage to the brake pedal position switch and the switch is good, then only a wire exists between the switch and the stop lamps.

 

Thanks for your reply. "88 definitely has separate flashers for turn signals and hazards. The Hazard one is behind the glove box. The turn signal one is at the fuse box. Tried them both just in case. My Haynes diagram also shows one wire from Brake switch to Hazard/Multi func tion switch, but they leave out the multiple connectors it passes through. Tried the switch too! Wire continuity checks good. I'm suspecting a wiring problem, but the diagrams in Haynes seem very "basic"

Thanks again.

 

Hope you have good luck finding it! I also hope you have a nice warm garage to work in. It got down to zero here last night here in Kansas. I hate working outdoors on the truck in subzero weather.