Part 1: Fry-free FSJ
And along came a craigslist deal that seemed too good to be true: a completely rust-free ’78 Cherokee Chief with a super-clean interior for $500. Why? The ammeter went all napalm-city on the wiring harness. It’s a common occurrence in pre-’79 AMC-era FSJ pickups and SUVs. Welcome to AMC-ville, kids; a land where quality wiring doesn’t exist. Over time corrosion and vibration wreak havoc on the barely-adequate wiring and connectors. And once enough resistance builds in the ammeter, poof goes the wiring loom. Ours was good and toasted, but we forked over the cash just the same.
It wasn’t until we got home and gave it a good looksee that we realized how bad it really was. The red and yellow leads going in and out of the ammeter must’ve gotten red hot, ’cause all the insulation was burned off ’em. Worse still, every wire inside the harness close to these heavy-gauge ammeter leads was melted and fused into one big cable of sparking, arcing mess. There was simply no saving the stock wiring.
Cue cheesy ‘60s Batman music and to the computer! A quick Google search later we were reading all about Z&M Jeeps Ltd and its FSJ replacement wiring harness on ifsja.org. The inter-dweeb scuttlebutt was positive, so we called up Z&M owner Zack Heisey. We could tell Heisey was passionate about Jeeps in general, and FSJs specifically. In addition to offering thousands of replacement parts for almost any Jeep, Z&M obtained the original specs for the much-improved ’79-’85 FSJ harnesses and had them exactly reproduced. The great thing is that Jeep didn’t really change much on the new ’79-’85 harnesses, which makes them nearly a plug-and-play upgrade for the crappy ’74-’78 vehicles. Heisey promised us many great things from his harness, but we kinda rolled our eyes. Yeah, we’ve heard that one, dude, but nothing is ever as good as promised. We figured we’d get the usual mess of a harness that we’d have to lengthen, solder, and modify. No way, campers. When Z&M calls this a true factory harness, it means it. Other than some very minor differences between the model years that we were forewarned about, the new harness from Z&M slammed right in place of our old, fried stocker. The harnesses can be purchased separately or all together. In our case, we used a dash, engine, and headlight harness. Two rear light harnesses are also available, as are harnesses for pickups. It’s not exactly cheap, but in this case you absolutely get what you pay for. If you’ve got the money and a ’74-up FSJ that needs wiring, you’d be stupid to buy anything else.
Since we were already under the hood and getting all electric-geeky, we took the opportunity to scrap the Duraspark distributor and ignition box for a full ignition system from MSD. The MSD Ready-To-Run distributor will let us easily tailor our spark curve as we make engine mods in the near future and the adjustable built-in rev limiter will definitely prove useful. Think dyno. We topped it off with a Blaster SS coil, 8.5mm Super Conductor plug wires, and the company’s Pro-Clamp wire separators. And since the battery that came with the Jeep was as sad as the rest of the electrical equipment, we nabbed a D34M Optima Blue Top. We’ve been Optima devotees for decades and we know if we ever add stuff like a winch or off-road lights it’ll handle it without puking.
Cappa calls it The Monkey Bus. This author assumes it’s because he affectionately calls his three boys his monkeys and plans to use the Cherokee as a family camping, fishing, and fun-type SUV. Let’s hope it’s that and not that Cappa has signed us up to shuttle diseased lab monkeys to and from gigs at biotech facilities. Either way, tune in next time when we’ll give you a full overview of our new rig and start chipping away at all the other stuff that’s wrong with this FSJ.