Where is the fuse for the brake lights? I am pretty sure that I popped it.
I am in the process of rebuilding the wiring in my tail light assemblies. I had power at the brake light wire on the harness that plugs into the assembly and the I did something that caused that power to no longer be present. Power went out in both assemblies at the same time. I have checked all the fuses under the dash for good continuity so I am hoping that the brake light fuse is somewhere else.
The other wires for running lights, turn signal, etc. have power still
Maybe check the brake switch at the brake pedal box.
The fuse should be the center box , not the driver side box . I can look tomorrow.
Schematic B-2033a for '89 ORED (from Forum library) shows the clearly marked fuse in the big block under the dash cover.
It's also in that same location on our '93 model.
https://www.foreforums.com/index.php?media/item/b-2033a-1989-ored-nighthawk.4837/#item_main
Thanks Chuck, my configuration appears to be a little different I think. These are the fuses for running lights etc and all test well for continuity across the fuse. Two of the fuses on the left side have had the descriptors worn off but one reads "interior lamps" I think and I can't make out the other... it also ends in "lamps" though. Either that's my brake fuse or it's somewhere else. According to the diagram, the only other thing it could be is a bad switch on the treadle valve or a short to ground that miraculously appeared as I was working on the wiring harness.
Stranger things have happened, so wouldn't rule anything out.
And Yes, your setup is entirely different from later models. Later model GVs use blade type fuses, not glass tubes.
That fuse panel is a Dodge motor home fuse assembly. You might be able to find something online that would show what each fuse does. The blade type fuse holders were General Motors if I remember correctly.
So I have no power on the left side terminal of the treadle valve regardless of if the brake pedal is depressed or not. The line coming into the right terminal is always hot regardless of if ignition is on.
I have been running these tests with the engine off, I am not entirely sure how the inside of the treadle valve functions, could lack of air pressure prevent the treadle valve from functioning?
Well son of a gun, that's a mistake I'll only make once. :headwall:
Treadle valves increase the voltage going to the brake lights based on how much air is passing through them. No air, no power. We must have had air in the tanks that whole time I was testing and then ran out right at the same time as I was jumping power to a second set of brake lights I installed, making me think I blew a fuse :o
Thanks for the help guys... it was the wiring diagrams that ultimately got me looking into the treadle valve. Wasted a couple hours but learned something new ^.^d
Sorry to not have expanded upon my prior post. Really busy with race season.
Call anytime.