A/C Not Working

tjmorton

New Member
Joined
Jul 19, 2020
Messages
24
Location
Fort Worth, TX
Hello all, I've wanted a Jeep since I was a kid and finally made it happen last week. 2001 Wrangler SE. Would have preferred the 6cyl but I'm pretty pumped regardless. Jeep has low miles (114k) and some upgrades (lift, 33s, winch etc) but does need a little work. Since I live in TX and its summer first order of business is getting the AC working.

AC does not blow at all. I've checked fuses and relays and everything is good there. Replaced the blower motor resistor, still nothing. Noticed the compressor clutch wasn't coming on so jumped the relay and got it going but still no air coming through the vents. With clutch engaged I hooked up a gauge to the low pressure line and appears to be low charge so tried adding 134 but no dice and noticed that lines started to freeze up.

AC work is a little beyond my depth so looking for a little guidance. My next step was going to be to replace the blower motor but would like to know if I should do some trouble shooting elsewhere first.
 
@TJ4Jim seems to have some A/C experience, so I'll tag him in this.

However, have you tested the blower motor to see if it's working? It's easy to test, and I would rule this out before going any further.
 
Thanks for the reply Chris. I have not tested the blower motor, planning on doing that tomorrow, but it's definitely not coming on at this point. Would an inoperable blower motor keep the compressor clutch from coming on? That's what I'm thinking but I haven't found anything via google searching to confirm that.

I have a buddy who's had a number of TJs and he suggested replacing the control panel but I have pulled it out of the dash and inspected it and as far as I can tell it appears to be fine, no obvious wiring issues from what I can see.
 
The blower motor and clutch engagement do not have anything to do with one another, either will function without the other.
For starters it does sound like the blower motor is bad, does it blow any air at any time (with the selector is any position, Heat, Vent, Max, or defrost at any blower motor speed)?
As far as the compressor, what was the pressure on the low pressure line prior to adding refrigerant and after. You said the lines started to freeze up when you were attempting to add refrigerant, do you mean the low pressure line? If so then that is a good sign and is normal since you had the compressor jumped and the blower is not working.
 
You need to get the blower motor working before you check refrigerant pressures and add refrigerant. The readings you would receive would mean nothing at this time.
Test the fan motor electrical leads at the motor for voltage; if there isn’t any then the speed selector switch may be your problem; if there is voltage the motor windings are bad.
 
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I did not have any good components in my HVAC system. Had to replace everything except the dryer, which I have discovered should have been replaced with the compressor. Live and learn.
 
Just had this issue.

I had a wiring harness melt behind the control panel. Rewired it and did the blower motor same time. Super easy.. remove battery.. remove the computer board (like 2 bolts) pull out the blower motor (like 3 bolts), unplug and plug in tje new one and put it back together.
 
Thanks for the input guys. I confirmed the blower motor is bad, getting power but not working. As far as I can tell all the wiring looks good but will double check when I get to replacing the blower motor. I'll replace the blower motor and go from there.

John mentioned that the blower motor and compressor clutch work independently of each other. So, does the fact that the clutch engages when jumped, but ONLY when jumped, indicate to you guys that the clutch is probably functional but won't engage due to system needing freon? The pressure reading on the lower pressure line was about 20 when I was attempting to add freon. Not sure how accurate that is though since the blower motor isn't working.
 
The pressure reading on the lower pressure line was about 20 when I was attempting to add freon. Not sure how accurate that is though since the blower motor isn't working.

That is low on Refrigerant, the low pressure switch works between 40 and 25 PSI, you had to jump the compressor because the pressure on the low side (suction pressure) was below 25PSI. When you get the blower motor working, you will need to add some Refrigerant. If you can get a manifold gauge set that would be best but you can charge the system using only the low side assuming that the high side is ok (compressor valves, orifice, etc). Use the following chart below for low side pressures vs ambient temperatures.

1595275066591.png
 
That is low on Refrigerant, the low pressure switch works between 40 and 25 PSI, you had to jump the compressor because the pressure on the low side (suction pressure) was below 25PSI. When you get the blower motor working, you will need to add some Refrigerant. If you can get a manifold gauge set that would be best but you can charge the system using only the low side assuming that the high side is ok (compressor valves, orifice, etc). Use the following chart below for low side pressures vs ambient temperatures.

View attachment 178297
Thanks John! I really appreciate everyone's input. Looking forward to getting the AC working and then moving onto project #2, steering and suspension.