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You may be able to lift up the fuse box. It should have 3 screws on the bottom and that will release the wiring harness from it. You could just cut the circuit out and install a inline fuse holder or see if you can find a empty fuse holder in the box that has both connectors in it and wire it into that as long as that circuit can handle the load. I put quite a few fuse boxes in when I worked for Chevy.
 

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This is what it looks like with the bottom removed.
The heavy gauge pink wire in the center of the photo is where your problem is.
The feed circuits are 3-gang terminals.
The bottom has catches around the perimeter you release to remove it.
Post a photo when you get it apart.
I have almost all the parts to repair or build new the UHFRC if you need anything.

Engineering Computer hardware Electronic component Electrical wiring Electronic engineering
 

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I have almost all the parts to repair or build new the UHFRC if you need anything.

View attachment 655175
Oh that's cool, that was one of my concerns because I didn't think you could get the parts anymore to fix these. I'm looking at buying a dually in a few months and it has this very same UBEC. I'm assuming that UHFRC stands for under hood front relay center. We always called them under hood bus electrical center.

Happy Thanksgiving everyone! Enjoy your day and eat way too much.
 

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All the 95-up GMT-400's, gasser and diesel, and some others use the same UHFRC (under hood fuse relay center - per GM)
I've had the parts for quite awhile, I'm sure they are scarce now.
I build harnesses for the 6.5 diesels, exclusively, so I have 98% of the parts these rigs use.
The easiest way for ya'll may be to snag a few from a u-pull-it.
At a minimum remove the firewall conn. (C100) and cut the harness about the center of the firewall.
If it is a DIESEL try to get the whole harness, it will remove without cutting any wires.
Then you can remove & replace any damaged wires you need already terminated, especially the heavy gauge stuff.
 

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Discussion Starter · #86 ·
That’s my guess as to what I’ll have to do. I’ve gotten it to drive though briefly and it’s running decently so far. I know it’ll wiggle out so I’m keeping it really close to home.

is there a way to get it out and the bottom removed without cutting the harness?

also, thank you all on this forum and happy thanksgiving. The advice is invaluable.
 

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You can get the UHFRC loose and turned upside down, but you cannot remove it from the harness
unless you take it completely apart, not recommended.
Be sure to remove both battery positive cables before working on the UHFRC.
 

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Discussion Starter · #88 ·
Hi Glagulator,

thank you for your expertise. I might dig further today. The Fuel SOL fuse location is what I think is loose.

the fuse itself has a bunch of play in it. I can now start the truck and it’ll drive for a time but then die. If I push down the fuse or replace it then it’ll fire back up.

one side of the fuse essentially gets a little discoloration but it doesn’t break. This leads me to believe one part of it is bouncing around in there making intermittent contact.

is there a way to tighten up that connection without yanking the box with a pick as a temp fix before I can try to find another harness?

I might try tightening it up with a wire on one side so it makes good contact but that’s more of a last resort.
 

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Get the PDM out of the engine bay, are you trying to cook it?
You might want to read the entire post before criticizing the OP....in post#52 he clearly states that he is not using either extension harness on either PMD...he has the PMD loose while testing. Also, get your terminology right....it is "PMD" not "PDM". Lol.
 
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