Wiring

I've read more than once that the charging system and battery wiring are inadequate in XJ's, and that it's sometimes advisable to run larger cables in key areas.


Which wires, specifically?

The obvious one looks like it's chassis-to-neg-terminal, as there doesn't appear to be one of those stock.

http://www.olypen.com/craigh/charge.htm

This gives you a pretty good idea of what to upgrade. I think there's other links out there also. Might try a search in the "Modified" section as I think it got discussed in there.

Let's see...

I replaced the main battery cables (battery-starter and battery-ground) with cables made from 2/0 Welder cable, as well as the cable for the alternator output. I also moved the power distribution from the post on the start relay (I've got Renix XJ's) to an aftermarket brass distribution post from Gall's Public Safety Supply, and ran 2/0 to that.

I also used a 2 gage cable to tie the alternator case to a chassis ground, and got rid of the aluminum braided engine-firewall ground and made a new one with one of my 2/0 offcuts, so no more ground trouble there, either.

And, I added a direct battery-chassis ground, with the rest of my 2/0 welder cable.

I like welder cable because it is flexible, easy to handle, and will take anything the underhood environment can throw at it! Figure on paying about $2/foot for 2/0 gage, although that size is overkill (you can use 1/0 or 0 without any problem, and even going to a 2 gage is probably fine. I just happened to have a big chunk of 2/0 from a prior job.)

You will need to get a crimper for cable that size - a "hammer-driven" tool will run $25-30 and can be powered by a good heavy claw or ball pein hammer, but I use a 4# drilling hammer because I have one. Make sure to put Ox-Gard inside the lug before you insert the cable, and I also suggest using heat shrink tubing to cover the lug shank and seal it to the cable insulation for added reliability. Keep these cables off of the exhaust and out of moving parts, and they should last forever! I went with overkill on all my primary cables for two reasons -

1) I already had the cable.
2) I've got some heavily modified parts (180A alternator, high-speed starter. Built by my local shop for a nominal fee...)

Go to a welding supply shop for the cable, lugs, and crimper. I haven't measured, but 25' of cable should take care of just about everything with some left over.

5-90

Thanks guys!

I won't be going for extreme overkill, but I have some leftover 2GA from a friend's stereo install so I'm sure some of that will find its way into the XJ in key locations Other than that, depending on price I think I will pick up some 6ga for the 10ga stuff mentioned in that link.

Well, what I ended up doing was taking some 10G and running it parallel to the 10G from the positive terminal to the powercenter, then running a 10G from the battery negative to a good, solid bolt on the frame.

I also replaced the beat-up looking lead terminals on the battery leads with brass hardware.

I haven't touched the alternator yet.


I can tell you though, even just that little extra wire that I put in there significantly brightened the headlights! If anyone's got an old XJ with the wimpy wires, I give this super cheap super quick upgrade two thumbs up :cheers: :cheers: