The #8 fuse under the hood was blowing on my '00 F-250 every time I turned on the healights meaning I would lose power to my park lights. The brown wire coming from the back of the headlight switch showed a dead short to ground that I traced to somewhere between the switch and the firewall.

Anyway, I got tired of trying to pinpoint the ground fault, so I cut the brown wires at the back of the switch and under the hood at the top bolt-on electrical plug and replaced the bad section with a new wire. It works fine now with the only exception being I do not get the park light flash when I hit the remote lock button the second time. I do still get the horn chirp.

My Haynes manual indicates there should be a relay box with a Park Lamp relay, Driver Unlock relay, All Lock Relay, and All Unlock relay. The park light relay looks like it sends the blip of power to the park light circuit. Can anyone here tell me where this relay box is? I'd like to splice into the brown wir coming out of it to restore the light flash when I lock the truck since sometimes it's too noisy to hear the horn. Thanks!

 

hi

I don't know that there is another Relay Box I think they mean the Relays in the junction Box and the other.

best regards

 

This is from memory, I read it somewhere here. They are on the forward firewall up under the dash, kind of behind the radio.

Essentially where the Vehicle Security Module would be on later model trucks.

 

Yep. That's where it is. Here is a pic. The brown wire is right next to the tan wire so careful because it's hard to tell them apart with your head down in there. Have a bright flashlight handy.
This photo was taken when I installed the SPED mod so the diode and splice connector are not stock items. If you are curious what the SPED mode is then here is a link:
SpringerPop's Disabler

 

Thanks! At least now I know where to look. Hopefully, getting the lower dash off isn't too big a job.

 

The lower dash is a piece of cake....once the upper dash is removed. Did you check out the link to the engine disabler mod? On same home page there is another great write up about adding upfitter switches.
SpringerPop's Upfitter Switches
The first three photos show how to get that out. Basically, you remove your radio to access two 8mm hex head screws. Once you have those screws removed then you can pull the upper dash panel off. It's held in place by several spring clips around the perimeter so take your time and be careful. If you have an assortment of blue plastic pry tools from Harbor Freight they seem to help make the job easier...

With the upper dash removed the fasteners to the lower dash will be exposed and you can remove that pretty easily. I think there are 2 screws on top, 2 on the bottom edge (by the transmission hump), 2 at the ash tray and 2 inside the ash tray opening. (going from memory here...)

With that stuff removed, you can see the parking lamp relay back in there. It has a black plastic cover that pops off to access the relays. If you have to trouble shoot a bad wire then you might have to unbolt the relay bracket from the firewall to see the wires behind (like my photo showed...)

Good luck!

 

I did check out the link to the disabler modification and found it quite interesting. The additional pictures of the relay block were a help too.

Had the upper dash off the other day to get to the headlamp switch wiring. (Next time I'll know to try to unlatch the thing from the back side.) ounds like it won't be too much trouble to get to the relay block now.

Thanks again!

 

The engine disabled mod is one of the best things I've done to my truck. My wife's truck has it also. It works really well and is a great idea that Pop came up with. It's totally something you can handle as well. Not really that hard if you break up the work between two weekends. Since you will already be into your dash that far...

 

So I finally dug in there and got to it. I cut the brown wire and spliced the wire from the relay block into the wire I ran earlier to bypass the gound fault. Now the lights blink with the horn when I lock the truck.

I could have sworn the lights used to blink twice though if a door was ajar. The horn chirps twice, but the lights only blink once. Is this right? I wish I had changed the relay when I was in there for I now fear it was damaged flashing to ground. Should replacing the relay restore the double flash, or am I just imagining that the park lights used to flash twice if a door was not closed?

 

Horn beeps twice with door open. Lights only flash once. Sounds like you are golden.

 

Bitster52 2000 F250 Super Duty

Shane-N-Bake, you still available for a question? I found this thread and discovered the relay block with door lock relays in pic above... was testing the "park lamp relay" to see if it clicked when park lamp switch was turned on... and nothing. However I heard something clicking somewhere... and found that on the blinker relay block one the small rectangular relays that was functioning when I turned the park lamps on and off. Why is this, is this my park lamp relay? Also what does the park lamp relay power as when I pull the relay that is clicking, with park lamp switch on, they continue to stay lit? Is there anywhere that shows what all these hidden relay blocks power? Why are they not in the owners manual and is there a manual that tells what each is with a diagram??? Also I tried to click on your link for the engine disabler... didn't get anything, what is it??

Thanks Bitster52