'88 Starion ESIR; 85 degrees outside, about 95 in the interior. Temp setting on the Dash A/C Control Panel turned on and the temp setting set at 65 DEG, economy turned off.
However, I can't get the compressor clutch to engage unless I hot wire the compressor clutch.
Things that I checked:
Dash A/C Control Panel lights up, I can change temps & get the beeps, orange lights light up & beep when various buttons on the panel are pushed.
Engine cooling water temp A/C temp sensor on the goose neck - tested sat.
Fuse for the A/C clutch compressor clutch - sat.
Jumpered the A/C dual pressure switch - clutch won't click or engage.
Jumpered the pressure switch - clutch won't click or engage.
Checked the compressor clutch relay - tested fine. In fact I changed the original with another sat tested relay - clutch won't click or engage.
Cleaned the power wire to the clutch connector - clutch still won't click or engage. No power to this connector with A/C turned on.
With all of the pressure switches jumpered, hooked up a jumper wire to the clutch power supply connector and WWWAAAALLLLAAA!!! Clutch engages. Let the engine run at idle with the A/C on for about 15 minutes and it cooled down the car interior and all of the radiator fans and the condenser pusher fan worked correctly.
Removed the jumper wires from the pressure switches only, and the A/C system worked as it should (fans operated correctly and so did the control panel) but the compressor is still hot wired.
Reading the FSM, Page 24 - 77 it says that if the clutch won't engage with the pressure switches jumpered out, and the fuse is sat, then the Thermister should be checked.
The FSM shows a line drawing of the thermister but doesn't show it's location under the dash ( I know it's by the evaporator ) or on which side of the evaporator it is. Driver's side or passenger side?
Does anyone know where this POS is and how much of a PITA is it to remove.
BTW where is this so called A/C system diagonistic connector (B - 75), as shown on the '88 FSM Page 24-68, that is supposedly by the ECI computer diagonistic connector? Everyone I have talked to about where it is tells me they could never find it. Got a picture to locate it?
Will I damage anything if I run a jumper wire from the battery + pole to inside the car; install a toggle switch and run the wire to the A/C Compressor clutch power wire connector with a 10 Amp fuse in series on the circuit? As the car interior gets cool I'll turn off the switch and when it starts warming up I'll turn on the switch. This will be temporary "fix" until I find the gremlin in the A/C circuits.
If the thermister checks out good, does anyone have an idea what else the problem could be?
For What It's Worth.
Edit - I looked up the Thermister in the '88 parts catalog, page 24-39, and I "think" that it's #9 Air sensor '88, MB27 6657. Can anyone confirm this?
Edited by Starfighterpilot, 13 June 2009 - 09:23 AM.