I have a '99  3500 dually, and I just noticed that all of my marker lights are out. This includes the ones on top of the cab, the ones on the rear fenders, and the ones on the tailgate. All of the regular parking lights work (fronts inside the blinker assemblies & tail lights) and the dash lights too. I suspect that a fuse has blown but I can't decipher the legends on the fuse box covers. Is there a seperate fuse for the marker lights, & if so, where would it be located?

 

Thanks for the help,

 

Joe in St Louis

Fuse F in the power distribution box under the hood. It should be a 20A fuse.

Thanks Mike,

 

Update: Seems that I was too quick to condem the cab lights. My first ispection was done in full daylight; when it got darker I checked again and the cab lights were illuminating, but the marker lights on the bed & tailgate are still out.

 

I checked the fuse you mentioned. The cover on the distribution box indicates that fuse F also supplies power to the fog lights *which my truck has) and they work fine. I will dig in further on the wiring under the bed - had problems there before.

 

Thanks again for the help!

Test light is your best friend

Test light is your best friend

I whole heartedly concur! The next place to check for a problem would be the rear of the truck where most guys tie in the trailer plug wiring.

I whole heartedly concur! The next place to check for a problem would be the rear of the truck where most guys tie in the trailer plug wiring.

If there is any Scotchlocks make sure to repair the wires properly solder and shrink tube and get rid of the Scotchlocks.

Sorry I didn't get back to this sooner to close the gap. I found some green globs of stuff representing a crimp connector of some sorts inside the corrigated loom on top of the rearmost crossmember back by the bumper - all the connections came apart in my hands. Interesting to find that two wires (hot & ground) from each  of the four marker lights, plus the two wires from the R/H licence plate light were all fed by the one quick disconnect plug in the harness. I ended up splicing the L/H & R/H markers together (8 wires into 4, 2 hots & 2 grounds) then spliced the four each hots & grounds together. All sealed up with heat shrink & covered with electrical tape. Look good, last long time!

 

And yes, the test light & I became good friends!

 

Appreciate the help,

 

Joe in St Louis

Glad to hear you got it fixed Joe! Good going!