Can someone help please? The ciggarette lighter, washer fluid motor, tail lights stopped working...Replaced fuse #15 several times in black box near fender, still blowing out after working for 15-30 minutes. Any idea? Any help?
Unless someone comes up with a better idea
Isolate( unplug /disconnect ) as many of those things that you can. Slowly hook them back until the fuse blows.
I’d probably start by focusing on the tail lights.
They have the most wiring and chances of the wire rubbing to ground.
Problems with each individual light. Check one, then the other.
I stopped buying Freightliners in 1991.
Some M-2 owner hopefully will come on and say it’s probably.....,,.....
Yes, likely a bad ground. Either the chassis module or bad frame ground usually at the back lights. Pretty common actually. May require some ohms testing as that is more predominate than voltage testing. Modules are very sensitive to shorts and ground problems.