Hello all! I replaced the turn signal switch in this vehicle over a year ago (at the time, I had no brake lights or turn signals) and when I did, everything worked. Now, I have no brake lights, however, I do have functioning turn signals and hazard lights. My brake lights do not light up on the vehicle nor on the dash when the pedal is depressed.

I have tried a test light on the two brake switches on the firewall (I assume they are brake switches, they are kind of round and bulb type with a few wires coming out of them) and I don't have any power anywhere on either of them. When I connect the terminals together with a screwdriver, I don't have any brake lights either.

I know when we were trouble shooting this last year, the brake switches acted the same as they do now. It was then I replaced the turn signal switch and it all worked. Before I dump another $140 or so on a switch, I wanted to find out if there were any other avenues to go down to test. I have looked all over for a service manual for some sort of wiring diagram, but I have just come up empty.

I hope someone can help. Thank you!

 

Was searching online and found used service manuals and wiring diagrams
http://www.faxonautoliterature.com/1994-Ford-L-Series-Foldout-Wiring-Diagram-L8000-L9000-LT8000-LT9000-LN7000-LN8000-LN9000-LNT8000-LNT9000-LL9000-LTL9000-P24724.aspx
I bought a set of wiring diagrams for 19.95. I am currently troublshooting the same problem. Both switches in engine bay tested good, but no power. Truck was overhauled in Feb 2012 Vendor has three different check points where they have to be verified to work before it can leave plant in Ohio. but it has been two other places since. One of them "borrowed" wiper control and caused a couple of other problems which I am also trying to figure out. Other than that it is a great truck. Do not know why Ford sold the line off.