Rear Running Lights blowing fuses.

[TX Bella]

I noticed that my rear running lights(daytime running lights and at night when the headlights are on) were not working. I replaced the fuse which continued to burn out. I checked the bulbs seemed fine. Removed the bulbs to see if there was a bad bulb socket, the fuse continues to burns out with no bulbs installed. The running head lights, marker lights, signals and brake lights work fine.

There must be a short somewhere nothing obvious I could find.

Any thoughts?

Thanks,

John

[DavidL]

Get a schematic, find out if there is a disconnect somewhere to isolate portions of the wiring harness.  Look at where the wires go into chassis holes to see if something got abrated and shorted.

Wiggle and check.   Wiggle other areas and check.

Basically you are going to have to isolate where the issue is and narrow in.

Edited March 6 by DavidL

[Larry Maida]

This is gonna sound weird but look at all exposed wires underneath. There has been a serge of rats chewing through wires especially if your coach was sitting along time. Also during these really cold nights if you are plugging in your block heater you are inviting then in and they like to chew wires. Just saying. 

[Dr4Film]

You have a positive wire that is shorted to ground somewhere, need to find the culprit.

[CorinthWest]

99 times out of 100, this turns out to be bad wiring on your trailer hitch.  Sometimes, like someone else said, it's hungry critters, other times it is caused by bottoming out the rear of the coach and pinching the wires against the receiver, and then other times is it simply shoddy workmanship or deteriorated wiring.  If this isn't it, I would start looking at the clearance lights for a pinched wire.

[cbr046]

Remove all the bulbs and put a light in place of the fuse.  When the light goes out you've found your short.  Better yet, use a low power noise source.  Wiggle wires and listen for breakups in the sound. 

- bob

 

[CorinthWest]

cbr046:  Good post.  Snap-On makes a neat tool for finding shorts too.  But definitely, when all else fails - start "wiggling".  LOL

[TX Bella]

Thanks for the input, The search begins.