I've got a 97 F350 Powerstroke with a wiring issue. I keep blowing fuse #8 (courtesy/domelight, electric mirrors, doorlocks, speedometer, buzzer/chime) when I open the door. It also blows when I turn the headlight switch to the left to activate the domelight. The mirrors, doorlocks, courtesy lights and speedometer work fine if I replace the fuse while in the truck with the doors shut but it blows immediately if I open the door. I don't have a wiring diagram (yet) and wonder if anyone has some guidence for troubleshooting this circuit. Thanks.

 

Sounds like you have a short somewhere and its grounding out. But based on what you said Id say its in your dome light wiring which runs from your dome light across you headliner to the back of the acb and down the inner track to the floor boards under the carpet in a small track on the driver side and about the front of your seat iturns ang oes into your rocker panel channel. The reason I say this because when you turn yourr dome light on it energizes the wiring for the dome light and shorts out the system and the same when you open your door, again the system would be energized as the door would ativated the dome light but with the door closed and the dome light off everything works. Now Ive had this before I have a fire extinguisher and flash light mounted to the floor board directly next the seat and dvr side door and when I screwed them down I managed to perfectly hit the wiring pack and the the threads of the screw barely shaved the insolation of one wire enough to touch a single strand of copper and blow the fuse the same way so if you have anything screwed in the general path if the wiring as i was decribing it I would check it and or remove the scres one by one and then replace the fuse and see if it still does it, if it stops it youve found your cause assuming it isnt make contact with the cab somewhere.

 

Thanks for the quick reply. That's about what I figured. Not sure where the wires ran and where to check first. I did pull both domelights off the ceiling so they couldn't complete a circuit and no more blown fuse. I put the front one back in and still no blown fuse and the light works fine. I'll try the back one next and I'm sure it will blow. I'll trace things down the pillers and across the rocker panel covers to see if I can find the culprit. Thanks for the assistance.

 

Wiring diagrams are available in my webshots. Click the picture in my sig and you will see the diagrams folder.

 

tjbeggs, thanks for the diagrams. Exactly what I needed.