2002 international 9400

If your cab and trailer have no lights, those are separate relays. I would think there is no power coming out of the switch or not going through the interrupt switch. I think power for that circuit comes from F3-D.

 

Resurrecting this post from the past...
I have a 2000 Eagle 9400i. Without warning, the headlights, running lights, tail lights, and brake lights stopped working. They worked fine yesterday... Go figure. Any ideas? It looks like there is no power running to the fuses for them (F3-B, F8A, B, C). Is there another relay before the fuse panel that would tie into all these together? At this point I'm wiggling wires looking for a short. Any ideas would be appreciated.

 

Power for those fuses come directly from the battery stud B2 to the left of the breaker panel. Chances are you have a 3+1 low voltage protect battery system where in low voltage conditions the B2 power supply stud is electrically cut off from the rest of the truck. To the left of the breaker panel is 2 big power studs. Normally there is a copper bus bar that connects the two studs together. If you don't have the copper bar, then you have the low voltage disconnect option. You can simply connect both of those studs together with a heavy cable.

 

Heavyd, you nailed it! The batteries are new. Checked the posts and sure enough, the one on the right had no power. Could not figure out why so ran a jumper between them and all is well. Thanks!

 

Yeah, there is a power module that senses low voltage and disconnect that power. Basically a big cut out relay. The module is located near the floor in front of the passenger seat. They do fail and are costly to replace. Not worth it. We just install a heavy jumper too.