Jeep Cherokee Electrical Upgrades

by Dino Savva

The factory 12v power cables and grounding cables are adequate on a stock Jeep Cherokee but for me, adequate doesn't cut the mustard. If you plan to upgrade to a higher output alternator to compensate for any extra electrical items that you've added to your Jeep (e.g. high wattage ICE system, driving lights, electric cooling fans, air compressor, winch), the stock power cables would no longer be man enough for the job. The grounding cables would also be inadequate and that braided strap cable going from the cylinder head to the firewall is a joke!

Old Cables

The first task is to remove those wimpy 8AWG factory cables. ALWAYS begin by removing the grounding cables first. You have three (battery to block, battery to inner passenger fenderwell, and that joke of a cylinder head to firewall strap cable). Getting to the 18mm nut that holds the strap cable to the rearmost driver's side head bolt is a real PITA so make sure you have a socket wrench with TWO swivel joints, otherwise you'll be doing a lot of cussing to get it off and get it back on again!
Then you can remove the 12v power cables (battery to starter and battery to power distribution center (PDC)).

New Cables

Now you can install your new man-size cables but before you do that, you'll need a pair of heavy duty brass battery terminals. If you're not confident enough to make your own cables, I suggest you buy the complete set from John Kelley (aka 5-90 in the NAXJA forum):

Kelley's Works in Progress

I was confident enough in my own fabrication skills and I could easily find the raw materials (welding cable and loops) so I chose to make my own. Thanks to the info. on John's page, I was able to copy the specs of his cables for my '92 XJ and installed them in the order shown below (red positive cables must ALWAYS be installed first, black negative cables ALWAYS installed last):

1) 28" length, 3/8" x 3/8" loops, Battery to Starter RED 2AWG
2) 12" length, 3/8" x 3/8" loops, Battery to PDC RED 4AWG
3) 10" length, 3/8" x 1/2" loops, Head to Firewall BLACK 4AWG
4) 45" length, 3/8" x 3/8" loops, Battery to Block BLACK 2AWG
5) 6" length, 3/8" x 3/8" loops, Battery to Fenderwell BLACK 4AWG

When I get around to swapping in my new 130amp alternator to replace the factory 90amp unit, I will also remove the old alternator output to PDC/B+ cable with fusible link and replace it with:

6) 24" length, 1/4" x 3/8" loops, Alternator Output to PDC/B+ RED 2AWG
7) ANL fuse block kit with 150amp fuse

Extra Ground Cables

To close the "grounding loop" (battery to block, block to firewall, firewall to cylinder head, cylinder head to battery, battery to inner fenderwell), I added two extra cables; one from the block to the firewall, and the other from the cylinder head to the battery.
I used 2AWG black welding cable and crimped on heavy duty loops at each end. The cable specs are:
Block to firewall: 26" length, 3/8" x 3/8" loops
Cylinder head to battery: 31" length, 1/2" x 3/8" loops

No chance of having any grounding problems on my rig!