12V Short

[JoeHogan]

Looking for guidance from someone experienced in tracking down a 12v circuit short. The basement light circuit has a dead short in it, somewhere. When the circuit is powered, switch on, the fuse fails. What is the best way to isolate the area with the short?

 

[turbopilot]

Looking for guidance from someone experienced in tracking down a 12v circuit short. The basement light circuit has a dead short in it, somewhere. When the circuit is powered, switch on, the fuse fails. What is the best way to isolate the area with the short?

These can be hard to find. Suggest you trace out the wire with a wire tracer. If you can't find it then rewire the circuit to each light.

 

[J&JD]

Why not try disconnecting the hot wire at all the lights and then reconnecting one at a time until the fuse blows.

 

[JoeHogan]

A tracer will arrive tomorrow. My first approach is to determine the direction of the series and disconnect each light. Check the wires for continuity between positive and negative leads. Once there is continuity that should be the bad harness, in theory. There is a light next to the hot water tank which is not accessible without uninstalling the hot water tank. Odd place for a light as it cannot be reached at all. My guess is it was installed by error when coach was mfg.
Then I’ll confirm my findings with the Tone tool. Should be an interesting exercise.

 

[Neal]

I had an issue where my basement lights wouldn't work but I was not shorting a fuse. I got really really lucky and when I had my pegboard off I noticed a relay just dangling in between the gray/black tanks and the white (ground) wire was loose. Complete stroke of luck finding this but the point is Newmar uses relays, at least on my coach and there was a loose wire.