A/C woes: low pressure switch

txbemis69

txbemis69

was last seen escaping the asylum
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a couple weeks ago i hopped in the jeep (eugene) on a warm day to make a run to town and noticed no cold a/c.

local shop recommended by a coworker checked it out and said no doubt it needed a new compressor.

was not sure that i believed this mechanic so i spent a few minutes later in the day troubleshooting by jumping the low pressure switch plug with a paper clip and came to the conclusion that hopefully a low pressure switch might be all it needed since the compressor kicked on.

parts store had to order a new low pressure switch which i picked up and replaced old with new yesterday after work. lucky for me the a/c is blowing cold again.

just another reason to fix your own stuff as not everyone can be trusted. $35 low pressure switch and a few minutes of my time for the win.
 
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txbemis69 said:
just another reason to fix your own stuff as not everyone can be trusted. $35 low pressure switch and a few minutes of my time for the win.
Click to expand...
Amen. You would've paid for the new compressor + labor, and you still wouldn't have had it working, and you'd have to pay for additional troubleshooting which should've been done in the first place. There's actually a section in the FSM for troubleshooting this exact thing.

I don't know if shops are dishonest or just lazy, but both generally end up costing you extra money in the long run.
 
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The are too many shops solely in business to make money off of uninformed customers.
These shops KNOW that a lot of their customers DO NOT know much about their vehicles.
The customers are willing to believe the services suggested by these shops; are really what is needed.
Learn about your vehicle.... BE AN INFORMED CUSTOMER.
There are reputable shops, but sometimes they can be difficult to find....
 
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txbemis69 said:
a couple weeks ago i hopped in the jeep (eugene) on a warm day to make a run to town and noticed no cold a/c.

local shop recommended by a coworker checked it out and said no doubt it needed a new compressor.

was not sure that i believed this mechanic so i spent a few minutes later in the day troubleshooting by jumping the low pressure switch plug with a paper clip and came to the conclusion that hopefully a low pressure switch might be all it needed since the compressor kicked on.

parts store had to order a new low pressure switch which i picked up and replaced old with new yesterday after work. lucky for me the a/c is blowing cold again.

just another reason to fix your own stuff as not everyone can be trusted. $35 low pressure switch and a few minutes of my time for the win.
Click to expand...

When you swapped out the low pressure switch did you have to evacuate the system? I bypassed my low pressure switch and the compressor turns on. Pressure seems good. When I went to start taking off the low pressure switch it started releasing refrigerant from the line (I’m guessing) so I quickly tightened back the old one. Does it leak out all of the refrigerant?
 
JKP said:
No, there is a Schrader valve under the switch. FSM available under Resources.
Click to expand...

The 2006 TJ FSM shows that the low pressure switch is on the accumulator. On my 2006 LJ it on the actual line itself. When I tired removing this from the line it seemed to start leaking. Is this just what was left in the line?

IMG_6799.jpg
 
JKP said:
The moved the location, that is the same as mine.

The switch depressed the schrader valve when you screw it on.

RTFM...
View attachment 636952
Click to expand...

Yeah that's what I read as well. So you're saying that if I fully remove the low pressure switch it will stop releasing refrigerant? Basically I unscrewed it a little bit and it was releasing refrigerant but if I were to go back out there and fully take it off it would stop releasing? I've got a new low pressure switch ready to go, I just want to make sure I don't completely drain the system when I do this. Thanks.
 
Yes. Once you unscrew it far enough the schrader valve will close. So, unscrew it quickly. Same with putting it back on, the switch will depress the valve at some pt and start releasing refrigerant until you get the switch seated.
 
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JKP said:
Yes. Once you unscrew it far enough the schrader valve will close. So, unscrew it quickly. Same with putting it back on, the switch will depress the valve at some pt and start releasing refrigerant until you get the switch seated.
Click to expand...

Amazing! Thanks for the help. I've never messed with any A/C unit before.

One last thing, anything I should lookout for with removing the old o-ring and installing the new o-ring on the new low pressure switch? Just wanna be sure about that before I go out and get this done?
 
You are supposed to lube the o ring with new compressor oil. There will probably be enough that leaks out in the valve to put some on it though, just make sure it's clean or you will have a leak.
 
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JKP said:
You are supposed to lube the o ring with new compressor oil. There will probably be enough that leaks out in the valve to put some on it though, just make sure it's clean or you will have a leak.
Click to expand...

Oh, glad I asked. Any other grease you may recommend maybe as an alternative?
 
JKP said:
The moved the location, that is the same as mine.

The switch depressed the schrader valve when you screw it on.

RTFM...
View attachment 636952
Click to expand...
UPDATE- So I went to swap out the low pressure switch. When I fully took the old one of it was leaking the entire time until I screwed the new one on. Would this mean my schrader valve needs to be replaced then? As for right now the A/C is working (not as cold as it was) but I’ll see tomorrow and see if it works then?

Was also a bit confused about where the o-ring goes? I put it directly on the line stem and not inside the new low pressure switch. But when I twisted the new new one on the o-ring looked like it got messed up…
 

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