ok 1. my a/c compressor is not kicking in so i checked for voltage none was going in. 2. i checked the relay and that seems to be fine i switched the relays of the ac with auxilly fan (they had the same #s on it) and it made no difference.3. i dont know what else to check or where to go from here. By the way i dont think there is any refrigerent in it right now(i dont want to fill it up unless i can get it working) and i know the compressor work i jumps the wire from to compressor to the battery and it kicked right in. Thanks for any help it will be greatly appreiciated.

 

I haven't worked on any AC systems since my head injury, so I might be a little foggy, but the compressor won't get voltage because of the low-pressure switch. (If system's empty/low). Jump the lp switch connector to check for voltage at the compressor. Do not operate in this configuration.

 

where is the low pressure switch i only see one wire

 

does anybody know how much oil goes in the system like ounces or cans. also im thinking of getting the freeze 12 stuff

 

anybody

 

Here is whats in a FSM for a 93 cherokee, hope this helps...Tj

REFRIGERANT OIL & REFRIGERANT CAPACITY TABLE (LIGHT TRUCKS/VANS)
(1) Oil Refrigerant
Application Ounces Ounces
Chrysler Corp. (Except Jeep)
Dakota ...................... 4.6 ...................... 44
FWD Vans (2)
With Rear Unit ............ 13.4 ...................... 50
Without Rear Unit .......... 6.7 ...................... 36
Pickup & Ramcharger ......... 4.6 ...................... 44
RWD Vans
With Rear Unit ............. 9.3 ...................... 65
Without Rear Unit .......... 7.3 ...................... 45
Jeep
Cherokee .................... 4.6 ........................... 38
Grand Cherokee (2) .......... 8.0 ........................... 28
Wrangler .................... 4.6 ........................... 32
(1) - Total system capacity, unless otherwise noted.
(2) - Models use R-134a refrigerant and PAG (ND8) Refrigerant Oil
(Part No. 82300102).
COMPRESSOR APPLICATIONS
NOTE: Due to late changes, always refer to underhood A/C
Specification Label in engine compartment or A/C compressor
label while servicing A/C system. If A/C Specification Label
and specifications differ, use label specifications.

 

The low pressure switch is on the filter canister on the frame rail. It is a two pronged switch. If it is not working, it means you don't have enough refrigerant in your system. It is a safety switch to protect the compressor. You can jump it but don't do it for more than a couple of minutes. You need to check your system out and look for wet oil spots around fittings and hoses. if you find any, and you will, get them fixed. If you charge the system it will only bleed off again and quit.

 

it might not be kicking on because there might not be enough refrigerant in the system. it will not kick on if it's to low. I would start there. and if it's full Then I would start checking relays and fuses

 

thanks everybody i bought r-134a kit retrofit today and will install tomarrow will let know if it works or not

 

i put the kit on the r-134a port was already on but not the high pressure port also i put in 3 12oz cans that came with the kit and it hit 26 on the gauge is this normal or should there have been more

 

Refrigerant temperature is proportional to temperature... is it 30 degrees outside?

 

no i believe around 70 also after the second can it was on 25 psi and after the 3 it only went up like 2 psi. i drove around for a few minutes and checked again and it was still around 27 or 26 psi

 

with the engine running???

 

yes

 

That's fine, then.

The temp chart is for "static pressure"

Low-side pressure will hover around 25-30 psi with the system running.

How does it cool?