Have a 2005 6.0, keep blowing the fues #17 that is for the dash lights and running lights. Have ckecked all bulbs and pig tails with no bare wires or bad bulbs. If i put in a new fuse it will blow within 2 min just by its self.
Any thoughts?????

 

blown fuse only means one thing--overloaded circuit, which usually means a short to ground somewhere.

 

Unplug instrument panel.

If that solves problem, you isolated it to panel.

See my writeup re bulb plastic base / metal rebuild.

Also possible place --- dash HVAC controls.

If it is not there, it is circuit by circuit isolation until you find the short, chafe wire.

But check the panel bulbs first...

 

Don't forget to check the rear bumper area at the 4/7 pin trailer plugs. Pinched wires and water or moisture.

 

Rusty... good one...

That is actually higher probability than panel.

 

Had a little trouble with mine awhile back.

 

The trailer plug wires are fused separately from the truck lights. If his short was in the trailer plug, it would be blowing the trailer tow fuse, not the running light fuse.

 

You don't know if it is an ad hoc wiring job that just took power from a convenient wire.

 

Highly unlikely. But please, keep the entertainment coming.

 

Thanks guys for the feed back, will try the dash cluster unplug in the morning and update.

 

Yup, Sorry about that Texas 6.0. Getting my trucks mixed up. My 90 GMC 1500 had the trailer plug wired to the truck tail lights. No instrument lights meant no tail lights either. When the RV shop put the 5th wheel hitch on my F250 they blew a fuse and it was specific to the trailer plug.

 

Pulled dash:
1) Disconnected gauge cluster and all that is connected to the main dash, light switch, radio etc. == Fuse did not blow but had no way to test running lights.
2) Reconnected the light and dimmer switch, == fuse blew about 45 seconds with the running lights on.
3) Reconnected gauge cluster with everything else disconnected == fuse did not blow but had no way to test running lights.

Does this mean the problem is in the wiring between the light switch and the lights themselves?

 

Unfortunately, once that circuit leaves the light switch, it goes all over the place. Does the fuse blow with the switch off? Or with the switch in the parking lights position, or with the switch in the headlights position. If you turn the instrument light dimmer all the way down, does it still blow?

And do you have autolamps? If so, put the switch in the autolamps position and cover the sunload sensor so the lights come on. See if any fuses blow then. It might be a different fuse in this test.

 

The fuse blows once either the auto lamp comes on or when you turn the switch for the running lights. Note: the head lights are still working.

If i pull all bulbs in the headlights, rear lights, running lights in the mirrors, plate lights and the rear cab light will this cause an incomplete circuit? Once all are pulled will i identify at least the possible problem area by installing one bulb at a time?

 

Unfortunately I don't think that will work. It's a fairly simple arrangement where the wire splits and goes to all the bulbs and the bulbs are grounded at each location. The short has to be somewhere between the switch and the bulb. It's probably a wire rubbed through and shorting to ground somewhere.

Turning the instrument dimmer switch all the way down should eliminate all the instrument lights.

I really only have a couple suggestions. The first one is kind of off the wall but if it takes a few seconds for the fuse to blow, try putting a new fuse in, wait until it's dark and have someone turn on the switch. See if you notice a bulb that doesn't light up, or is really dim, before the fuse goes. The circuit to that bulb would probably be where the short is. You might go through a fair number of fuses doing this but, who knows, it might work.

The other thought would be to find the main harness going to the back of the truck and unplugging it. That would isolate the lights at the rear anyway. Then if the fuse still blew you'd know it was in the front, and if it didn't you'd know it was in the rear. Theoretically you could do the same thing with the front lights, but I don't exactly know how to say where the main connectors are for those lights.