Ford Powerstroke Diesel Forum banner

DEAD dash after blue wire mod...PLEASE HELP

5K views 4 replies 3 participants last post by  Calkidd 
#1 ·
I did the blue wire mod for my fan clutch. I used the upfitter pass through wires to gain access to the inside of the cab (the truck does not have upfitter switches). After doing this mod the dash shuts off, no windows, no radio. However, I also get a glow plug open circuit DTC error code on all 8 glow plugs. The blue wire mod has been disconnected with no change.

Here is what happens:

I start the truck everything operates ok. After about 20 - 30 seconds I hear a click from a relay in the inside fuse panel and the gauge cluster dies with no power to the windows and radio. The engine does not die. After cycling the key off and turning the truck back on it does the same thing.

If I just turn the key on and not start the engine the cluster does not turn off and every thing works fine, its only after starting the engine.

Even unplugging the fan clutch I still get the same results.

I also get the P0671 through P0678 errors codes. Even after clearing the codes they return once the keys is cycled and the truck is started again.

I am really stressed out because we are leaving tomorrow with the toyhauler for a camping trip. Any help would be greatly appreciated.
 
See less See more
#3 ·
Yet another reason for having some sort of monitor...

Glad ya figured it out!

-jokester
 
#4 ·
Don't ground your blue wire mod to the dash, ground it to something solid in the engine bay. The wimpy metal in the dash can cause a ground loop.
 
#5 ·
I wanted to give an update to this post just in case there are others that have read this and might be scratching their heads. Even though I usually go back through and check what I did different I had forgotten one step that was causing this problem.

This is all because of the OEM charging cable that runs from the alternator to the passenger battery positive post. Even though I am using a 2/0 awg cable to run directly from the alternator to the passenger battery you MUST keep the OEM charging cable attached to the battery. This is what powers the GPCM and the 12v power to the alternator's 2 wire plug. By removing this cable it will give you the glow plug DTC codes P0671-P6078 and cause your alternator to overcharge. I am lucky I didn't damage any electronics even though I did get a FICM over voltage error code.

I had removed this smaller cable thinking I didn't need it anymore. So the blue wire mod did not cause this as it was totally operator error.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top