Spruced up the "new" wiring harness

I wanted to upgrade my engine's wiring harness to the new one available from BJ's Off-road, but it won't work with my year FSJ. The problem is that the various engine connectors changed so much during the late 80's as a result of AMC's penchant for using parts from a variety of different manufacturers from year to year (Ford distributors and carbs, GM ignition modules, etc.) and Chrysler's purchase of Jeep from AMC. My next best option was a used wiring harness that I could recondition before pulling my own, which is the route I went.

Zach at Z&M Jeeps in Ohio sent me a used wiring harness he pulled from an '88 GW. I was able to look it over on my dining room table and fix any cracked wires, clean the connectors, re-grease all metal prongs with dielectric, and wrap it in braided sleeving from Painless Performance. Here's what I started with:

It had plenty of old electrical tape and grime on it, but it was largely free of cracks. The few I found, I repaired with a double-ended crimp connector (don't know the technical name) and then wrapped 'em in fresh tape. Where needed to help hold a cluster of wires together at a branch off the main harness, I used some additional electrical tape. I then went nuts with Painless's Powerbraid and zip-ties. Yes, it's overdone, but I wanted it clean, tight, and manageable, all of which it now is. Nothing gets tangled, and I have confidence that it will flow juice where it needs to go on a consistent basis.

Overall, I was quite pleased with what I received from Z&M and with the clean up job I did. While I could have simply pulled mine and refreshed it, I wasn't inspired to trust it due to some wiring gremlins I'd had in the past and the nest of wires (mentioned and photographed in earlier posts) between the alternator and the passenger side fender. I'll keep my old one as a hopefully unneeded backup.

Steering box brace and roof rack

The steering box brace is one of those upgrades that will only serve a purpose off-road, but it was worth it. Right now, my steering box is performing beautifully--no leaks, easy and fluid turns, no slop in the steering wheel at all. What this brace does, thanks to TT Fabworks, is lock the steering box tight to BOTH frame rails. (It's bolted to the left rail as its standard mounting point, and this brace ties it as well to the right.) As a result, in an off-road situation the box mounting points won't be stressed or torqued much, if at all, when the tires are in a jam.

The brace is a steel tube that T's into a flat steel plate that is bolted to the inner right frame rail directly across from the steering box. My frame rail might be slightly out of true from the earlier mentioned front right ding courtesy of the PO. As a result, I had to use some Grade 8 washers to adjust the fitment of the brace against the right rail (a space is welded into the bracket to account for the offset mounting holes in the rail itself). Before I added the washers, as the brace extended over to the steering box, it didn't line up properly for the mounting brackets. Two washers later, it's good. (While we're here, note the wiring nest up above the alternator in the background. That'll be dealt with soon.)

The brace clamps around the pivot shaft of the steering box just above the pitman arm. Once it's in place and lined up, with the nut and bolt on the outside of the steering box set loosely in place, just use a pair of vice grips to hold the longer legs of the bracket in place against the extension arm before drilling holes for the mounting hardware. This gets a custom fit every time, specific to each application.

This was a half-hour project, mainly because of the alignment issues. Here you can see the brace in its entirety.

And now for the roof rack.

I found this roof rack on the same '88 GW at the San Bernardino PAP. I and several others on the IFSJA forum are picking this rig clean. It was $18 out the gate, and it's in great shape. Now, most FSJers refer to these as vanity racks because they aren't as rugged as a safari-style rack. But those are hundreds of dollars, and I don't like to carry a lot on top of my vehicles anyway, so this'll do for me.

To get the project started, I had to pull the headliner trim pieces and drop my exceptionally ugly headliner down a few inches to access the underside of the roof. Then it was a matter of disconnecting the dome lights and rear seatbelt attachment points so that I could drop it down fully.

That's when I learned a little more about the complexity of the project at hand and the usefulness for doing it. By pulling the headliner out completely, I could see the roof support cross-members, two of which were dented/sagging (the one farthest forward in this pic and the one closest to me).

Here's a closeup showing how the cross-member is supposed to be attached (with some kind of adhesive) and is bent down.

My solution of choice. I use some industrial adhesive, a 4x4 leftover from my new fence, and a small carjack to get the roof and the cross-members back into some semblance of their original position. An inelegant solution, to be sure, but I'm just looking for better, not good. Besides, I bought this thing in part because it was ugly and in need of some knuckle-busting.

Below you can see the sinkholes in the roof (those metal slats are supposed to lay flat across the roof). I just worked my way around the passenger compartment, jacking up the dents and then using some metal screws to hold the roof up tight against the slats.

In the pic above you can see the mounting holes for the rack. Apparently a little rubber grommet with a metal thread insert is supposed to go in each of those holes. As a small torq-head bolt is screwed into the grommet, the rubber expands to fill the hole and hold everything tight. Um, no. I tried and was not successful in any way. Perhaps the mounting holes were expanded by a previous owner--who knows. So plan B, which should have been plan A, was sprung into action. I found some steel L-brackets, cut them at the bend, and used them to mount the rack to the roof. Here's an undershot.

I used RTV in each bolt hole to help seal things up (you can see some squeeze out from the nearer end of the bracket). And then I caulked around every metal screw I used in the slats to hold the roof in place. It's definitely water tight and will remain so.

A shot of one of the roof rack mounting points. There's a plastic "seal" sits between the roof rack's foot and the roof itself. That also was treated to some RTV (I had a lot extra) to keep things sealed up nicely.

This thing is on securely. When I grab it and move it side to side, the entire Jeep rocks and there is absolutely no play in the rack itself. While I won't be hauling cinder blocks with the rack any time soon, it's certainly not a vanity rack anymore.

It was nice to make some improvements on the roof itself as part of the rack installation. At times, over large bumps, the roof would make a buckling sound (like when an oven cools after baking bread, if that makes sense). It doesn't do that anymore because of the increased rigidity of the repaired cross-members and the increased attachment points with the metal slats.

The final product...

Nath took this pic sitting up on my shoulders. He's quite the photographer.

Wiring up the fan

This wasn't too terribly complicated, except for the temp sensor that tells the fan relay to engage the fan itself. I didn't want it running all the time because that would only delay the engine warming up, which is part of the problem I had before with the stuck thermostat, so I had to come up with a more viable solution, which I did (by throwing a little money at the problem).

I'm not a fan of wiring nests, and the previous owner was a hack (the mess I had to clean up behind the stereo alone still boggles my mind). Unfortunately, however, the fan relay has a lot of wires running off of it, and its placement was limited by wire length (didn't want to splice any extensions on ). To keep the wiring clustered efficiently-ish and out of the way, I put the fan relay next to the starter relay on the passenger's fender inside the engine bay.

I'll probably come back to this area in the future and make some improvements in the layout and weather protection. Perhaps a plastic dome enclosure to shield it from random splashes or debris. I really don't want to damage the fan and have it die on me, leaving me stranded.

This was the slightly more complicated bit. I was hoping to use a manifold port for the temp sensor, but none were available. Essentially, this thing has to be in the coolant flow to know when the coolant temperature has reached the engagement point. It then sends a signal to the fan to turn on. (The engagement point is adjustable, which is nice.) The fan shuts off when the temp drops 10 degrees below that point, or when the engine is turned off.

My solution was to order an aluminum insert that gets put into the upper radiator hose, allowing the temp sensor to get screwed in there. There's also a ground wire to keep everything safe. I ran the wires down and around the battery and then back to the relay itself. It works, and it's out of the way of the moving parts of the engine. I'll probably wrap it in sleeving later.

I let the rig idle in the garage for about fifteen minutes, waiting until the fan engaged, which it did. The first time it spun, there was a bit of a rattle, but that sound hasn't returned since, so I'm okay with it. All in all, the new fan, the new radiator, the new temp sensor, and the new water temp sender are working as they should to keep the engine running cool and smooth.

New Crossflow Radiator, Electric Fan, Thermostat, and Water Temp Sensor

A while back, I noticed the occasional small puddle on the garage floor underneath the radiator core support. It was a slightly cloudy liquid, not at all like I expected coolant to look like. But there was nowhere else it could be coming from. I couldn't find the leak itself, but the age of the radiator hoses and the radiator itself (which is the original with the Jeep, I believe), it was time to make an upgrade. Having worked a bit extra this winter session at RCC, I had the fun-funds to make the upgrade. I went with the aluminum crossflow radiator and accompanying electric fan from BJ's, designed specifically to fit the Jeep's core support radiator housing. This is the best shot I have of the original--apparently, it was too ugly to document closely. It's the black lumpy thing to the right of Nath's right hand.

So here are the new pieces to go in. I'm replacing both the radiator and the mechanical fan to improve cooling. Excess heat kills engines and transmissions, so this is a smart upgrade and well worth the part of the afternoon it requires to install. The fan (a 2400 CFM unit which pulls rather than pushes air) comes with the aluminum shroud to improve efficiency. Since the shroud for my mechanical fan was gone before I bought the Jeep, this is an added bonus.

I couldn't reuse the brass connectors on the original radiator because they were too small. But getting the plumbing figured out just required a quick trip to the local Home Depot for a pair of straight and elbow brass hose connectors for the top and the bottom. Here they are, installed, along with the brass connector that runs from the fill neck to the overflow container on the driver's side fender.

Removing the old one was simply a matter of draining the original (a few gallons total, but it took forty minutes to trickle drain--see pic below); disconnecting the transmission cooler lines, as well as the upper and lower radiator hoses; and then removing a few bolts holding the radiator to the core support. In this pic, you can also see the green corrosion at the bottom of the radiator (top middle of the pic). The hoses running across the upper third of the picture are the tranny cooler lines that run transmission fluid through the cooler that sits in front of the AC condenser (see next pic). The hoses that run out the left side of that mini-radiator (the tranny cooler) were also replaced in the upgrade process.

So now the radiator is in and all hoses are hooked up. This new one has a built-in transmission cooler that I chose to use with my existing/stock cooler to help extend transmission life. The tranny cooler was in much better shape than the radiator, probably because it is protected between the AC condenser and the grill, whereas the radiator itself is subject to whatever gets thrown up into the engine bay.

A shot of the underside with new hoses connecting everything together. No more leaks, much better flow, and a happy (i.e., cooler) engine. (Note the tight tolerances between the engine pulleys and the electrical fan. There's about a half inch right now because the old fan's double-ended bolts were extra long. I'll replace them with capped bolts later to increase the spacing.)

On to the thermostat.

While the radiator was drained and the hoses disconnected, I wanted to replace my thermostat (which opens and closes at specific temperatures to allow coolant to circulate around the engine). I'm pretty sure the one in there was bad simply because the Jeep took forever to warm up--a common sign the thermostat is stuck open. Here's what I found when I popped the thermostat housing off:

Not pretty. Lots of gunk and orange rust in there, at least partly caused by the fact that the Jeep has been sitting for a while. Closer inspection with the thermostat out. Looks like standing water has been sitting on a cast-iron engine block.

I scrapped off the old seal off the top of the block and cleaned up the housing, sanding it smooth and getting off what rust I can. With the engine rebuild coming soon, it doesn't need to be perfect.

A little liquid thermostat gasket, and it was back on the block, tightened down, and ready for some hoses. While I was working in the area, I also installed a new water temperature sender on the manifold just behind the distributor. This is the thing that sends the temp reading to the dashboard gauge so that I can tell how hot or cool the engine is running. I'm not sure the other one was bad, but it's an inexpensive part worth replacing in light of all the other cooling system changes I'm making.

Here it is, all back together. Up next, wiring the electric fan.