1999 GMC k2500 7.4l build detail

[kunstmilch]

I had previously mentioned the issue with the traditional underwood electrical center was the maxi fuses. I looked up multiple alternatives from Bussmann, Gep Power Products, MTA, Dill Blox, etc... I had considered switching to J-Case fuses, Midi fuses etc.

After weighing out the pros and cons for my particular situation, I landed on Gep Power Products for the Underhood Electrical Center replacement. I began playing around with online configurators like the one provided by CEautoelectric.com (no affiliation, I dont have any affiliations by the way) and after a lot of back and forth, I came up with a solution I am still working on, below is some of the steps in the process for anyone who has to go through anything like this nightmare.

There are 2 main branches of wires feeding the UHEC. Here covered in loom. The traditional UHEC also has three B+ bolts. The two branches and 2 of the bolts can be seen here on the right side of the UHEC.


After Lots of pictures and studying the technicians manual to wrap my head around what is going on and what Im looking at here we began to slowly move forward. Here you can see the loom removed from the two branches. The one on the right is all the Maxi fuse circuits, the left is everything else.


Originally the Aux fan relay sat on an external "rail"


The cover has the index for my particular UHEC.


Here I'm testing out sizing of the system with the OE relays and a Gep 96 position PDM.


I bought 2 "project boxes" as a prototyping tool for housing the new UHEC. two sizes, here is the bigger of the two...no way this fits.



I downloaded the drawings and specifications sheets from Gep and worked them up in illustrator. Here's what the whole file looks like, ive got dimensioned drawings for all the iterations that are feasible and am able to play with them like puzzle pieces.


Here is the template cut out and the fitment.

 

[kunstmilch]

The Gep Power products Maxi fuse PDM moves away from the Aptiv system of terminals and instead uses the Lear Mak 8 terminal. The Lear terminals are quite robust and nice. There is one big downside as far as I'm concerned. Lear doesnt give good crimp specifications or have recommended tooling. This is really bizarre to me but here we are. So after talking with numerous people I bought a tool that was recommended for the job by two independent people with experience with these terminals. I am making a B+ bus to feed the Maxi fuses like the traditional UHEC.

Here is a bit of what that all looks like.

6AWG SRML and my preferred cutter for larger wire.


Cutting and fitting to size.





I like to add a drop of Deoxit D100 to the threads prior to the crimp.



There is also no crimper for the mechanical, or strain relief crimp. I had considered making a die but taking some time and slowly working the tangs with pliers (I used this wrench) worked out pretty well.


Heatshrink the fiberglass braid and install the terminal. It's a tight fit.


From the top.


ok, so now time to get it done...