Eagle

It could be the wiring between the sender and the cluster, or it could be a bad gauge in the cluster.

I use DOT-5 silicone brake fluid.

Check your wiring. Ignition ON (engine can be running, but does not need to be). 1. Remove wire from sender. Leave it hanging in air and observe gauge. Should be pegged at 80 psi. 2. Ground wire to a known good ground. Observe gauge. Should be pegged at zero psi. If this test fails, you have a broken circuit between the sender and the gauge.

The '88 and newer XJs and MJs have a ballast resistor in the fuel pump circuit. It should be a whte ceramic block about 3 inches long on the innder fender of the driver's side, near the air filter box. The ballast resistor reduces voltage to the fuel pump when running to reduce noise. The starter circuit has a by-pass so the fuel pump gets full voltage when starting. If you get power with the key in START but not in RUN, the ballast resistor may be blown. It can be easily replaced, but it can also be by-passed, either for testing or permanently. (The 87s didn't have it.)

Clogged catalytic converter?

3.73 gears with 31x10.50 tires is exactly the same as stock tires with 3.55 gears. I think 3.73s are the optimum ratio for 325/75 and 30x9.50 tires, but even for 31s IMHO 4.10s are a much better choice. With a 5-speed, the engine will NOT be "buzzing."

They are the same. The reason you see references to both is that the 4WD trucks had both. In the same truck. Remember, the front Dana 30 has a smaller ring gear and a smaller pinion gear than either a D35 or an AMC 20 (since you have an '86, the AMC 20 was the optional, heavy-duty rear axle). Because of the size difference, it isn't possible to make both with exactly the same number of teeth on both gears. So we get "mismatches" to the second decimal: 3.54 / 3.55, 4.10 / 4.11, etc. They came that way from the factory. That slight difference doesn't matter.

Personally I do think it's probably a bad ground at the horn, but that's only because that was the problem with the horn on my '88 MJ. The relay clicks, so you're good to that point. Next test -- get a helper and a test light, unplug the power lead from the horn and probe with a test light, have your helper push the horn button and verify that you have power to the horn. If you get power at the horn, the problem is the horn, or the ground. Run a supplemental ground. If that doesn't fix it, you may need a horn.

IMHO the ONLY single component that can cause both no spark AND no crank is the ignition switch. However ... on an old vehicle, sometimes multiple problems hit at the same time. Have you tried jumping directly from the battery to the starter solenoid to verify that the starter and solenoid are good?

Okay, so you wanted to splice rather than just use a factory plug. Your call -- I didn't see the original. When you spliced, are you certain you matched all the wire colors correctly? Did you solder the splices, or just twist the wires together and wrap with electrical tape? Since you have a plug in the rear harness, pull the plug, identify which wire feeds the rear taillights, and check that wire on the forward (body) connector of the plug to verify whether or not you're getting power that far. If so, you then focus on wiring from the connector back. If not, the problem is forward of the connector.

You do if it's an HO. The "O2 sensor" reminder lamp is turned on by the ECU. The thread title asks specifically about Renix.

You don't have a PCM ... you have an ECU. It doesn't in any way interface with the starter motor, so it cannot cause a no crank failure. I don't think that's your problem.

Bucket seats with a mini console? Doesn't sound original, but in the AMC days there was virtually nothing that was impossible. My '88 MJ is a Chief, which was one level above Pioneer. It has a grey fabric bench seat. It had to have had a mini console when new, but the previous owner had hacked the floor and there was no console when I got it. Mine also has dual side mirrors without the joysticks.

Headlight delay and lights-on buzzer were options in all years. My '88 Cherokee had both, but I don't recall if they were part of the Pioneer package or if they were ordered separately. Ditto for intermittent wipers. The Eliminator got bucket seats, full center console, tinted glass, and sliding rear window. I think it also got "manual remote" side mirrors, where the Pioneer and even the Chief had side mirrors that didn't have the joystick adjusters. I believe the Eliminator also had under-dash (footwell) courtesy lights. This Pioneer and Chief did not.

Here's another thought -- When you swapped in the AX-15 and matching transfer case, did you put the original speedometer drive gear into the transfer case? If not, you are running a speedometer that thinks you have 3.07 gears when you actually have 3.54s, and both your speed and distance readings will be whacked.

Something doesn't seem right. According to the BF Goodrich web site, a 225/70-15 tire runs 758 revolutions per mile. That's very close to a typical 215/75-15, which runs 754 revolutions per mile. With 3.54 gears and an AX-15 transmission, at 70 MPH you should be turning 3114 RPM in 4th gear, but only 2335 in 5th gear. Did you recalibrate your tachometer when you swapped from a 4-cylinder to a 6-cylinder engine? I don't think your tach is giving you accurate readings. I think you are actually turning closer to 2000 RPM. The factory didn't choose 3.07 gears with the 5-speeds for optimum fuel efficiency in the real world, they chose those gears to get better results on the arbitrary and artificial government economy test. In real life, 3.07 gears suck and 3.54 or even 3.73 gears should almost always result in better fuel economy on stock size tires. 3.07 gears have the engine running well below the torque peak at highway speed, and that's NOT the way to obtain better economy.

I assume you drove the front wheels right up into contact with this ledge, then tried to crawl up it from a dead stop? With 32" tires and a 2.5L engine running stock gearing, that's an excellent way to burn out your clutch, or break something. Stalling the engine probably saved you a big repair bill. The factory put a low range in the transfer case for a reason -- try using it.

What happens when the switch is in the parking lights position (halfway out)? But where and how did you tap the new rear harness into the vehicle wiring? Did you get a Comanche harness or a Cherokee harness? Did you remove your old harness at a factory connector and just plug in the "new" harness, or did you cut and splice to make te connections? Do the dash lights function when the headlight switch is in the parking light position? Do you know that rotating the knob of the headlight switch is the dimmer, and that if the knob is rotated all the way it turns off the instrument lights?

See your post #19. Looks like you have one thick shim on the driver's side, passenger side looks to have two thick shims and at least three thin shims.

And punctuation ... such as periods and commas. I recently read that using periods in text messages is considered insulting. No wonder people can't communicate any more. [/sermon] Did you splice in the new tail harness, or did you plug it in at a factory junction connector?

I very much doubt that any road is level. If it is, it was built wrong. Never mind what it looks like. You're trying to fix death wobble. Front end alignment isn't a game of "That looks pretty close," it's a matter of precision measurement. The human eye cannot see a difference of one or two degrees. Find some place with a flat, level floor. Check the floor for level with a 4-foot or 6-foot carpenter's level. And nuts probably don't have the top and bottom surfaces accurately cut parallel. Use a socket, as Don suggested.

When Hornbrod wrote "level," he meant "LEVEL" -- as in a flat floor that has zero slope in any direction. Make certain that all four tires are inflated to the correct pressure. If the vehicle isn't on a perfectly level surface, the readings you get from the angle finder are worthless. Your readings show 14 degrees of caster on one side and 16 degrees on the other. The printout from your alignment shows 9 degrees -- and even nine is too much, and hard to believe. When you can -- please jack up one side, remove the front wheel, and take a good photo of the upper ball joint. I've never seen an XJ or MJ ball joint with a castle nut like what I see in your photos. They should have a flat top with a zerk fitting in it.

A clogged catalytic converter usually results in loss of power.

Never heard of it.

Which part of the seat belt doesn't work? The short (female) end? The break because there's a flat steel spring clip inside that breaks. As far as I know that can't be repaired, so the fix is another seat belt. XJ belts work just as well as MJ. I think that short, inner section of the belt is the same length for both the XJ and the MJ.