Electrical this time, so guys bare with me. (1994 F150, 300-6, 4x4, 5spd)



Last night coming home, was cruising down highway at my normal cruisin speed of 55-60, and all of a sudden, my dash goes dark, and all my park lights turn off....great. Only head lights were still working. I quickly push in and pull out the ****, and my radio goes dead to..fantastic!


2 fuses burnt out. So been looking at it for hours today. I discovered my dimmer switch is bad, corrosion ate the dimmer spring, and the spring fell onto the metal body, so I figured that's why it shorted out.


So first I try figuring out the radio one. I put new fuse in, turn key on, fuse burns right away.


I disconnect my dimmer switch. New radio fuse in, key on....radio works, alright.


Connect new good used dimmer switch. Fuse blows without even putting the lights on.


So I cut all the wires from the harness plug going to the dimmer switch, to splice in a new harness connector witch I also had a spare of.


So I put a new radio fuse in, and let the radio play as I splice each wire from the harness, to the new harness plug.

I got to this yellow w/black stripe wire, as soon as I touched the matching wire from the plug, it blew the radio. So I left that one aside, new fuse in, radio playing again, and finished heat shrinking all the other wires.


All went well. So without that yellow w/black stripe wire, I pull the ****, and again, blow the exterior lighting fuse, but radio was fine.





I gave up now for today, cause it's getting cold and i'm not sure where to go from here.


Any ideas? Sorry for the long thread, but just wanted to explain in details.

 

Sound to me like a short in the wiring to the headlights. Here is a diagram of the headlight circuit. Might help.



1983 Ford Bronco Diagrams picture | SuperMotors.net

 

My head lights do work though. It's the park lights that don't.

 

So it's blowing fuses 4, 10, & 11?
And with the Y/BK wire disconnected it doesn't blow 11?

If so, pull fuse 10, then try reconnecting the Y/BK. If it still blows fuse 11,, follow the LB/R wire from the switch down to the fuse block looking for damage.
There also might be corrosion or debris in the fuse block...

 

Only 2 fuses burn out, #4 and 11.

11 burns out if I touch the yellow wires together. 4 burns out when I pull out the light switch.

 

Those 2 circuits aren't electrically connected anywhere. They both go through the light switch and the fuse block. I'd be looking at the wiring between the light switch & the fuse block, specifically the W/LB and the T/W wires, for damage. Maybe they've been chafing & grounding out...

 

Did you cut wires when you downgrade from 94 to early 90's headlight?

 

Nope, no wire cutting, and no wires were ever hacked anywhere in the truck except for an old Alpine radio, witch looks like it was a clean wiring job.

 

Well I was in for a suprise when I took the radio completely out. 3 wires witch I hadn't seen the first time I checked the radio wiring (checked it a few days ago as I plan to swap back in factory connectors and a factory radio), 3 wires that had been cut, and just left there like that, no tapped or anything. And one of 'em was that yellow wire from the switch that was blowing my fuuse.


Tapped everything up, and all good to go. Lights working again! What a silly problem that turned out to be! Thanks anyways guys!

 

Like I've said before, the worst problem our trucks have is the previous owners...



Glad you got it fixed!!!

 

Bubba strikes again.