94 a/c not excopting a charge

kpoindex08

Registered User
After work today I decided to e-vac my a/c system and re-charge it. Recycled old r134A from system then drew a vacuum on it for 45 min. it held vacuum. Took off the vacuum pump and started to charge the system. Jumped the compressor to suck all the goodies in and it only excepted 4 oz of fluid. Took the jumper off to see if it would engage by its self. It did not. Where is the pressure switch on these cars and can I by pass it?
 
I'll assume that you have the engine running and the blower fan on HI speed? What are your guages HI/LOW reading. Are you getting ANY compressor clutch activation?
 
maby 5-10 psi bolth sides! no clutch movement on its owne like i said i had to jump it to actovete it. yes car is running and on high.
 
With a vacuum on system did you get vacuum down to 30 " HG of vacuum?

i have never had to run the compressor to suck the refridgerant into the system. it should go in all on its own. the can or machine uses a much much higher pressure than the system and will push it in.
 
I have had to use jumper wires for the pump to make it cycle. You could have a plugged orifice which is common and pressure just won't get where it needs.
Make sure your pressure switch is connected too.
Alan
 
After work today I decided to e-vac my a/c system and re-charge it. Recycled old r134A from system then drew a vacuum on it for 45 min. it held vacuum. Took off the vacuum pump and started to charge the system. Jumped the compressor to suck all the goodies in and it only excepted 4 oz of fluid. Took the jumper off to see if it would engage by its self. It did not. Where is the pressure switch on these cars and can I by pass it?

The High/Low switch is on the reciever dryer pass side firewall if you jumper it the compresser cluch should engage if its turning but not taking freon you may have a clogged orfice.
 
Last edited:
Got it thanks for the help! Yes I reached 30 inches of mercury. (HG) held vacuum till I put hose on low side. And attempted to fill. But man do I feel stupid :eek: I forgot to turn on the valve to the supply line. Line had some pressure in it but not enough to cycle the compressor. Thanks for all the help and sorry it took so long to get back
 
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