Running light fuses blow, intermittent

[SandyEggo]

I have a 2010 Fleetwood Fiesta on a Ford chassis and need some help with an electrical problem.

The fuse for the running / clearance lights blows intermittently, especially over bumps at highway speed. It can be OK for an hour or two then blow fuse after fuse. It's a 20 amp circuit.

I have already:

1. Pulled and checked the rear clearance lights harness
2. Pulled and checked the front headlight / indicator harness
3. Replaced the front and back clearance lights with LEDs (they were cracked from sun damage anyway)
4. Replaced the headlight switch
5. Visually inspected the harness, front-to-back

I'm not looking for miracles but hope that someone on this group had the same or similar experience and could coach me in the right direction.

Thank you

[Old Scout]

If you have a trailer plug on the back of your rig for yr toad--might also check there??????

[SandyEggo]

Thanks Scout. I did pull the plug and should have mentioned that.

This will happen whether a trailer is connected or not.

[l1v3fr33ord1]

SandyEggo-

By any chance, the same fuse as on this active iRV2 thread?

Mark

[SandyEggo]

Originally Posted by l1v3fr33ord1

SandyEggo-

By any chance, the same fuse as on this active iRV2 thread?

Mark

It does look very similar and provided a few things to check into (thanks). I'm going to tag onto that post in hopes they have resolved the issue.

[Greg2]

When you replace the blown fuse does the replacement blow right then? If so, then replace the fuse with a light, [use pigtails on lamp]. Then you can trace down a wire for voltage. Where you lose it will be close to your short to ground.
Hope I did not lose you. But by temporarily using a light you can get voltage down a wire that is shorted to ground.
HOWEVER, if the fuse does not blow, the above info is of no help.
Intermittent electrical problems can be and usually are a bear to troubleshoot. Once they 'stay broke' though, usually they can be found somewhat quickly.
You could always just jump the fuse with a heavy wire and let the smoke out!!- NO Don't do that, just kidding.
Good luck.

[SandyEggo]

This morning I did find my problem and thought I would post this for others that may experience a similar problem.

It was a pinched wire, behind the drivers headlamp housing. It was pinched from the factory and apparently took time to wear through the cable wrap and wire insulation.

It now makes sense why it would blow on the freeway but not when going slow.

At freeway speed, the wind pushing against the front panel + bump = shorted wire

*Thanks for your help

[CLIFFTALL]

Thanks for the update. Great catch and will most definitely help others.