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About Minuit

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    MJ Maniac

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    Columbia, TN

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  1. Wish I had time to see what's inside of one of these things and see if I could fix it
  2. Wish I had time to see what's inside of one of these things and see if I could fix it
  3. In this situation, I would always suggest to use the factory gauge... with the stipulation that you use a MOPAR sender only. Aftermarket temp gauge senders are JUNK and not reliable. In my experience, they tend to read higher than a Mopar sender. Aftermarket oil pressure senders seem a little bit more consistent in my experience. Don't complain about how inaccurate the factory gauges are if you stuck crappy aftermarket senders in. The part number you want for most pre '92 applications is 53005309. On the "top" of the sender, there is a threaded stud that the connector attaches to. It does not have a plastic connector molded into it. Starting in 1992, the temperature sender in the rear of the cylinder head changed from a 1-wire to a 2-wire sensor. In 1996, the separate temperature gauge sender was removed and the gauge now pulls its reading from the ECU based on the sensor in the thermostat housing. If both your gauge and sender are working properly (with a MOPAR SENDER), the gauge's needle should be somewhere on top of the "2" in "210" in most cases. This corresponds to a coolant temperature of roughly 195 to 205 degrees. My '91 runs cooler than my '89 due to a larger radiator and the fact that the auxiliary cooling fan is on any time the A/C is on, which is almost always. Steep hill climbs in overdrive and sitting in traffic on extremely hot days are the only cases where I would consider a gauge reading above "on top of the 2" acceptable, and it should immediately return to where it was once you are over the hill or once you have started moving again.
  4. This. Be ready for some serious fumes if you pull the sender with gas still in the tank. The last time I pulled the sender in my '91 I had roughly 1/4 tank and I had to give it a while to air out under the truck before I could breathe.
  5. Maybe a silly question, but can you still see behind you?
  6. As a side note, I want to take this time to address something I've seen repeated quite a lot on this forum - that using "MAX A/C" is bad or runs the A/C harder than normal. In truth, it's actually putting less load on the system on MAX than it is on NORM. On a Comanche, two things happen when you switch from NORM to MAX: - The fresh air door closes and the recirculation door opens, meaning the system is pulling air from the cab and running it through the evaporator, rather than pulling in outside air. The cabin air is probably cooler than the outside air (unless you've been parked outside all day and just started the truck) so the A/C has less heat to get rid of. The longer you run MAX A/C, the cooler this air gets, so even less load on the A/C system! - At least on HO models, it increases the blower fan voltage by roughly 1.5V. That's all. The only component being stressed MORE is the blower motor. That's a valid concern to have, but it won't cause an overheating problem. In the long term, it may melt the fan speed switch if your blower fan is old, shaggy, and drawing too much current and you run the fan on full blast all the time. Even on extremely hot days, I don't need to run my fan on full blast to keep the truck cool (2nd fan speed usually does it, 3rd fan speed if it's REALLY hot), so if you do, you may have an A/C performance problem on your hands. So why does MAX A/C cause less load? Our MJs have an A/C system based on a high pressure cutoff switch and an evaporator probe. Some models have a low pressure switch too, but neither of mine do so we'll ignore it. Those are generally the two things that control whether the compressor is on or off. The high pressure cutoff switch prevents the compressor from turning on if there is no refrigerant in the system or if there is a dangerously high pressure in the system. The evaporator probe controls compressor duty cycle (how often it's on) based on the temperature of the A/C evaporator. Once it reaches a certain temperature (somewhere around 35 degrees, I think) it turns the compressor off. Remember, the evaporator is the part that gets the hot incoming air blown over it, turning it into cold air. The hotter the incoming air is, the more heat gets transferred from the incoming air to the evaporator. The more heat transferred to the evaporator, the more the compressor needs to run to keep the evaporator cold. MAX A/C generally pulls cooler air across the evaporator than NORM does, so the compressor doesn't need to run as much to keep the evaporator cold! I didn't REALLY mean to write a college heat transfer textbook here, but sometimes things happen. Have no fear about using MAX A/C. It's less likely to make your truck run warm than NORM. I pretty much always have mine on MAX. Using the A/C, no matter what setting, will add a significant heat load to the cooling system, so if your cooling system isn't up to the task, turning the A/C on might push it over the edge. If BOTH fans are working properly and your cooling system is in otherwise good condition, this should be no problem. It was 93 degrees this afternoon, and my temperature gauge stayed right where it should with a Mopar temp sender - right on top of the "2" in 210 even when at a stop.
  7. I dream about air conditioning all the time. Maybe I'm not the best example to go by though
  8. My '91 does not have the trim. Both of the older bumpers I have do have the trim.
  9. My first check would be fuel pressure. If fuel pressure is correct, my next move would be to heat the CPS with a heat gun to attempt to reproduce the failure...if you can fit a heat gun in there. If not, I'd try to make it happen again and check CPS output with a meter once the problem resurfaces. If you have to drive it, consider using something to cool the CPS back down. Canned air, bottle of water, whatever. Common trick I use to diagnose thermally-dependent failures in electronics. If hitting it with some freeze spray fixed it, that tells you exactly what part to replace. Or just take the easy route and wing a CPS at it if the fuel pressure is good. That works too, but I don't like to spend money I don't need to.
  10. The '92 wiring will have a LOT of small advantages and some big advantages over '90 wiring. A real exterior fuse and relay box, organized wire runs, the feeling that the thing may have been touched by an actual engineer, etc. Is that all enough to make me want to swap a harness? Maybe if I had to remove everything anyway or was starting from an empty shell. I don't think I'd rip an entire (functional or repairable) Renix harness out of a truck and swap it with an HO harness on its own, though. Lots of changes would have to be made - it won't just slot in unless you swap literally everything from an HO donor. One thing I would NEVER do is backdate an HO vehicle to use anything Renix. Even if it's all I had. I'd rather build my own harness than swap Renix wiring into anything it didn't come in from the factory.
  11. 50F is still a very good number considering the Renix era's smaller compressor and various other things. If I remember correctly you're using a stock replacement condenser too. At the end of the day, all that really matters is that YOU HAVE AIR CONDITIONING! A/C in my opinion is the one thing that is always, 100% of the time, completely worth the heartache and cost involved in getting it.
  12. Was that taken with an IR gun? I use one of these: https://www.amazon.com/FJC-2790-1-3-Dial-Thermometer/dp/B0002JMEVC/ref=sr_1_24?keywords=dial+thermometer&qid=1568162983&s=gateway&sr=8-24#customerReviews
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