I've replaced compressor & dryer, condensor fan, condensor fan relay, hi/lo pressure switch and vaccuumed the air from the system. I applied 12 volts to the compressor to filled the system with frein. When I turn the AC on, the condensor fan and compressor clutch won't engage. Any suggestions. Thanks in advance for any help.

 

I moved your post to correct forum for problems. Read posting rules.

With system vacuumed completely, open refrigerant (R134A?) to low side and allow pressures to equalize (1-2 mins). This will provide enough refrigerant pressure to close the hi/lo pressure switch and allow compressor to engage and charge the system,...assuming there are no other problems. It is not necessary to jumper the compressor clutch.

Did car hold vacuum for at least 15 mins? If not a leak is likely.

good luck

 

Yes it held vaccuum for 45 minutes. Its now filled with freon and the compressor fan and clutch won't engage. Have replaced everything except AC thermostat and ECU. Any suggestions.

 

Check whether you're getting 12V to the compressor w/ AC commanded On. If getting 12v and compressor doesn't close, then either too large clutch gap or open clutch coil.

If not getting 12V, something is preventing the ground signal from ECM to close ac compressor relay. Check ac pressure switch, thermostat, and AC panel switch for continuity (shorted). Any of these open will stop ECM from grounding ac compressor relay.

good luck

 

Only getting 9.6v to the compressor and the condensor fan. Should it be a full 12v?

 

A voltage of 9.6V is low for both. There is no significant resistance in series w/ either condensor or compressor, only wire, fuse and relay which should not drop voltage significantly. It should be over 12V.

Relays can sometimes develop poor contact and lead to high resistance.

Are you sure your battery is good?

good luck

 

Battery is definitely good, gonna change the compressor clutch relay tomorrow. Finally found a post where someone had the same issue and they changed both relays and I only changed the condensor fan relay.