BSDMotorSports

I'm working on a 92 Accord for a friend. The AC Compressor Clutch won't engage thru the normal on-off.
Both fans come on with the motor running, blower on, AC button & light on.
Checked freon pressure should be adequate to start the clutch.
Unplugged the low-pressure switch, condenser fan stops.
Jumped the low-pressure switch connector, condensor fan comes back on.
Re-connect the low-pressure switch, condensor fan comes on.
Swapped condensor fan relay with compressor clutch relay, fan works-still no clutch engagement.
Jumped 12volt directly to compressor clutch, clutch engages and system runs with good freon charge and cold air output.
Gone thru all fuses and am not finding any blown.
With motor running, blower on, AC button on, condensor fan running, none of the wires in the compressor clutch relay connector have power.
The compressor, clutch, fan, condensor, and expansion valve are obviously in working condition. Just can't get the system to turn on power to the clutch.
Has anyone had this or have any ideas????

holmesnmanny

What are your low and high side readings ? For some reason the ecu isn't energizing the compressor. Are you getting battery voltage at the compressor connector on the ecu side ? You might want to check the connector for the thermostat behind the glove box. See if it's still plugged in.

holmesnmanny

Looking at this again I think it could be your ac pressure switch that's bad, assuming you know that your refrigerant amount is good and there are no leaks.

BSDMotorSports

Thanks for the response.
The high side pressure is 155 and the needle hardly fluctuates.
On the low side, I normally watch the temp on the gage so don't know the pressure off-hand. It's just under 32, slightly low, but plenty to allow the pressure switch to work.
While I have the comp clutch jumped, putting 12v to the clutch connector, when I unplug the low pressure switch, the fan shuts off. I unplugged the low pressure switch and jumped it and the fan kicks back on. I'm pretty sure that tells me that the low pressure switch is working properly.
Nothing at the comp clutch relay connector is "hot". No voltage at the relay at all. The wiring diagram appears to tell me that at least one of the relay connector wires should have voltage anytime the ignition key is "on", but not sure.

Lost Again

There should (? using a POS manual) two BLK/YEL wires to the ac relay - they should have 12 v to ground with the key "on" - if not the manual say to check the #9 7.5 amp fuse in the under dash fuse box....or find the break in the wire.

BSDMotorSports

Thanks for the info. Problem solved. We checked all the fuses, but didn't have the dash fuse block layout. Got the layout and the #7 fuse position for the compressor clutch relay was empty. Go figure. Put a fuse in and The clutch works. Sometimes the obvious things take awhile to connect.