Minuit

The Weekend of the Drum Brakes '89: Both rear adjusters seized solid, passenger side brake shoes were put on backwards by a previous owner. Brake fluid looks like muddy water. Spend the afternoon putting new shoes and hardware on. Both rear brakes get plenty of fluid, but no brakey brakey. The shoes don't even budge. The only possible thing I can think of is seized wheel cylinders. Yay! '91: Decide I'm going to try and get the right rear adjuster working again. Remember how much I hate the 9" brakes on the c-clip D35s. After spending way too much time screwing with the stupid adjuster cable setup, it works for about 3 stops until the wheel cylinder on that side pops and fills the drum with brake fluid. Yay! Guess I'm going to the junkyard tomorrow for some ZJ disc parts. Drum brakes can my [REDACTED]

Mine is pretty cool right away. Gets better once you start moving but it's not a huge difference. What condenser are you running?

They spent $2400 having a BA-10/5 professionally rebuilt.

Correct. The seat design is entirely different. The pre-95 seats are an old Renault design. The later seats are a Chrysler design.

Seems like there's a consensus. Thanks guys.

Quick question, yes or no answer. I'll be doing an open cooling system conversion on my '89 soon. Mostly out of laziness, I'd rather keep the factory cooling fan setup with the switch in the driver side radiator tank. I'd also rather not swap the thermostat housing if I don't need to. Does anyone know off the top of their head if this radiator has the port in the driver side tank for the fan switch? It sure looks like it does, but I want to be sure. If not, is there an inexpensive radiator with a fill neck on it that does have this port?

Nobody told the Jeep 4.0 that pansy things like oil pressure and a functioning cooling system are needed for an engine to run. My 89 idled for 10 minutes with no oil flow at all before I noticed that it sounded a little clackier than usual (I also assumed that my aftermarket sender crapped out). Doesn't seem any worse for wear after that. Rebuilding the pump even brought the pressure at hot idle to within factory spec! I will definitely be trusting the oil gauge a little bit more now.

Thanks for reading (and tracking down the A/C label - I thought that was going to be impossible)!

I'd be very interested in what product you used.

I renewed the registration on it today and went for a quick drive. It drives exactly like it always has, and the oil pump rebuild has even brought it within the acceptable range for hot oil pressure at about 20psi at idle. The engine runs and sounds no different from before the incident, and I think I might try some of that Marvel Mystery Oil stuff in the oil to maybe try and free up what I'm pretty sure is a very collapsed lifter. Three things that need to be addressed soon - the front end hasn't gotten any better, the brakes are awful, and the cooling system doesn't hold pressure. Other than that, it's mint!

Yep. You'll also need to make holes for the latch on both the seatback and the bottom cushion.

I've noticed exactly the same thing on mine. @CptVanGuard - A stock MJ is an absolute tin can. Now that I'm putting my 89 back on the road, it's all coming back to me how noisy and unrefined these things can be. You're going to want to do a lot of deadening to make things livable, and I'm not just talking putting a few sheets of Dynamat on stuff. That'll help (and Dynamat is a quality product), but it won't bring the noise floor down enough for a true "audiophile" system. And then you'll no doubt have plenty of wind noise to worry about once you've done that. The doors on these are especially bad. They're twice as bad if you have power windows. It took a while, but I finally got my doors to stop rattling, but there's a lot of closed cell foam, MLV, and felt in my doors. The time and money spent on sound deadening makes just as much difference as the actual audio parts. The factory attempt at sound deadening consists of a square of vibration damper on each door and a piece of foam on the inside firewall. That leaves plenty of room for improvement. I've made life a whole lot harder for myself by being a fussy purist and insisting on a stock look throughout my interior. That limits me to the less than great factory speaker positions and a stock-looking radio, albeit one with some secrets under the hood. If you're the kind of guy that chases every percent of improvement at all costs, you'll probably be doing some custom installation sooner or later. Before you spend any money, do some reading on here and other car audio forums and come up with an idea of what you want out of your system. Making sure the sub and amps are going to fit in the truck is the big consideration. Make sure the parts you're picking work well together. For example, if you don't plan on running rear speakers (and my suggestion is to either forget about the rear speakers or use a DSP to control their frequency range) either buy a 2-channel amp or get one that can be bridged to 2 channels. For me, a component set of some type is a must-buy. The dash tweeter locations aren't very good, but having your left tweeter pointing at your shin is even worse. The best thing to do is build them into either the A-pillars or the sail panels. You may find that you want more flexibility than the passive crossover you got with the component set, so at some point you'll want to go active. That's where I am now. Pretty soon, I'm going to be building a custom "stock" radio with RCA outputs and going 2-way active up front, probably with a MiniDSP 2x4 HD. I'm 90% happy with the way my truck sounds now, but I know I can squeeze more out of it with some tuning. That being said, I'm always trying to squeeze every little bit of improvement I can, within the limits I'm willing to cross. You might do a headunit, amp, sub, and coaxial speakers in the doors and find that you're perfectly happy and don't want any more. That's for you to decide. I don't know your level of car audio experience, so I apologize if I'm telling you things you already know.

The only thing that jumps out at me is the shot looking into the interior from the driver side door. You can see signs that liquid has run down the floor. Maybe water, maybe clutch fluid, maybe something they used to clean it, but liquid in that spot always makes me nervous. Otherwise, pretty nice looking truck.

Woohoo! We have achieved oil pressure once again! I rebuilt the oil pump with a Melling K-81 kit (mostly for the gaskets) and put it together this afternoon. Everything went back together easily and the oil pump primed right up. The new gears in the kit are much tighter than the old ones. That may have been my problem to begin with - upon looking at them closely, the old oil pump gears had a fair bit of slop. The engine doesn't seem to have picked up a rod knock as I'd feared. It sounds more or less the same as I remember it, with a very pronounced top end clack, and it may have taken a slight hit to its oil pressure, but I think we can nurse this engine along a little bit longer. On to STEP TWO! Fun fact - the driver door won't close with the truck on jack stands.

195. Mopar thermostat strongly preferred.

Rear full-range speakers (just to be clear, I'm not talking about subs) are IMO worse than useless in an MJ. They'll throw off any imaging you have and sound like garbage in the process because they're going to at the very least have a seat between you and the speaker. I'm very iffy on "rear fill" in a car or SUV, but the MJ doesn't even have a rear to fill. My advice is to bridge your amp (if possible) and forget about rear speakers, especially if you have a component set that likes to be fed some power. When I had rear speakers in my MJ, the only thing they contributed was a NASTY ear-killing peak at 1250 Hz and another one at about 4kHz. As soon as I put components up front I disconnected the rear speakers and bridged my amp to the front. Much better.

The sub is probably the easiest part of all if you're going for a real system build, honestly. You'll have plenty of inspiration to draw from. Like Pete said, there are a number of commercially available boxes out there if you don't want to build your own, you'll just need to do some measuring to make sure they fit. Other than a sub, how crazy are you planning on going? Are we talking "new speakers in stock locations" or "3-way active in custom fiberglass enclosures" here?

That's just the first stop, but none of this stuff can work right in the RUN position if the switch isn't doing its job properly.

Pin assignments, from left to right. I-3 S G-1 B-3 B-2 B-1 G-2 A I-1

Got a multimeter with an ohms function? I'd be starting at the ignition switch. Look for a burnt up connector. If that looks ok, it's time to grab the meter and follow the chart on the right:

How are the speakers wired? Is it still the same as in the first picture? If not, can you post a new picture of the speaker outputs and describe how the wires are set up and where each speaker wire is going? That's only a 4 channel amp, so you're going to have to wire two sets of speakers together if you want all 6. Actually, I'd probably just leave out the liftgate speakers entirely. More speakers doesn't automatically make things sound better and wiring them in parallel could very well burn up your amp. Usually it just means there's 6 woofers and 6 tweeters (12 if you are using 3 way speakers) fighting over the same frequencies unless you're very careful with setup. My truck sounded much, much better the second I got rid of my rear speakers, but that's for you to decide once you get it working. Can you find out the exact model of the amplifier? I'm trying to pull up an owner's manual for it. Make sure the remote wire on the radio goes to the remote wire on the amp. Don't connect the power antenna wire to the amp in any way.

The ground wire carries the same current as the power wire. They must be rated for the same current as each other, and that number should be well over the actual current you expect the wire to see. Usually, this means making them the same size. You also want the wires to be as short as possible to minimize resistance, which is just another way of saying what Jeep Driver is telling you. Dzimm and jdog are correct about the power antenna wire. On many factory head units (at least the ones I deal with) the power antenna lead is always on when the radio is on. On aftermarket headunits, this usually isn't so. Aftermarket headunits will usually have a remote wire in the harness for this reason. The owner's manual for the radio should tell you color and connector position of this wire. Usually, it's blue/white. Connect that to the amp instead. If you aren't running a power antenna, the power antenna wire can and should be removed from the connector. The "speaker output" wires go to the speakers as you probably suspect. The + wire goes to the + speaker terminal, and vice versa. The + terminal should be labeled, and if they're a decent speaker, the + will normally have a larger (0.187") quick connect terminal than the - terminal (0.110"). If this were my installation, I'd feel a lot better using actual terminals on those screw-on amp connections rather than stuffing the wire in. What model is the amplifier? Is there a sub in this system? How many speakers are you running? What are the speakers?

You'll want to lubricate the window track and the winder mechanism too. Back when my 91 had crank windows, they were somewhat stiff but I never had any trouble breaking the cranks. I'll bet the little "snake" that runs the window up and down has a bunch of gunk in it making it unnecessarily hard to crank the window.

Yes. We all are. Like it or not, FB is the future. Whoever spouts out the most BS as loudly and as quickly as possible is the winner these days.