High beams blow fuse (1 Viewer)

[Scro]

When I activate the high beams the left headlight fuse blows. Low beams are normal and all other lights and electronics function as they should AFAIK.

I have removed the instrument panel and located the common ground which seems to be the source of a lot of electrical gremlins. I don’t see any indication of burning other than some dark spots inside the casing.

Does this look like it could be a source of trouble? I have bunch of different size pin removal tools, how do I know the correct pin out tool?

If the common ground isn‘t the cause of my short where else should I look? is there a safe temporary workaround? I plan on changing/gutting the dash in the fall.
Thanks, Trace

 

[OSS]

Swap bulbs on each side. See if the left side is still the problem

Install a next higher amperage fuse and see if it blows. Maybe the bulb is drawing more current than its supposed to.
A bad ground will reduce current. It won't blow fuses.

 

[Scro]

LED headlights lights. I have a cheap reverse polarity headlight wiring harness that I temporarily installed and the fuse still blew. I thought a bad ground would cause a fuse to blow…I need more learning

I have had a lot of wiring work done on the truck (out of state), speedhut gauges and a box full of PO wiring taken out the engine bay.

I tried some spare bulbs but the lights don’t have power with the gauges removed.

Any other suggestions?

 

[Randy88FJ62]

Stock sealed beams?

 

[Scro]

Stock sealed beams?

LED headlights.

 

[2mbb]

A short to ground causes fuses to blow, not a bad ground connection. Were you able to try what OSS recommended to swab bulbs left to right and see if the other fuse blows. Looking at the wiring diagram, I would suspect the bulb is bad. The bulb provides the resistance that controls the current flow. If there were a short between the fuse and the bulb, then the fuse would blow on low or high beams. A short after the bulb would mess with when the lights turn on, but not blow fuses.

If you have a different wiring harness, then it would be helpful to see what that is like.

 

[Randy88FJ62]

This, "I tried some spare bulbs but the lights don’t have power with the gauges removed."

You have some weird stuff going on with aftermarket wiring, a "headlight harness", and custom gauges. This is not something easily diagnosed through the FSM and a stock wiring system.

 

[Scro]

The truck is at a friends diesel shop, I’ll run over there and double check the battery cables and try the lights/bulbs again.
Thanks

 

[Scro]

Update.

The battery ground was loose, that’s why I didn’t have power.

I swapped bulbs and still popped the fuse.

I checked resistance and found the red/white wire has .239 resistance and the red/yellow has .493 resistance.

Installed a 20 amp fuse and it did not blow. I‘m using LED headlights from Cityracer.

I inspected a large portion of the wires under the hood (de loomed) and found no breaks or burn marks.

Next I will located the hi beam relay and check it for continuity.

Thanks for the help and please continue with suggestions.