lmdew Posted July 12, 2007 Share Posted July 12, 2007 I have a 98 Impreza Wagon that the AC will not run on. The following has been checked: - AC Switch light comes on when pressed - Fuses are good, relays are good - Jumping the pressure switch does not turn on the Compressor - The radiator fans do not come on with the AC selected - If the relay contacts for the compressor are jumped the compressor kicks in - There is no power at the coil for the AC relay The relay wires are as follows: Coil: Green-Red stripe and Brown Contacts: Green-Orange stripe and Blue I have several wiring diagrams, but none of them match up. It looks like the coil gets power directly from the switch, so pulling it and checking power there will be my next step. It would be Great to have the correct diagram. Thanks Larry Lmdew@hotmail.com Link to comment Share on other sites More sharing options...
Cougar Posted July 13, 2007 Share Posted July 13, 2007 Larry, My info shows the power going to the relay coil on a brown/red wire from a 10A fuse mounted in the AC relay holder. Link to comment Share on other sites More sharing options...
lmdew Posted July 13, 2007 Author Share Posted July 13, 2007 The wiring looks original. I guess I'll have to check the years before and after and see if the wire codes changed. There is power at the switch, but not full power coming out of the switch when everything is hooked AC control panel is hook up. Something is diverting power, wiring fun! Link to comment Share on other sites More sharing options...
Cougar Posted July 13, 2007 Share Posted July 13, 2007 Did you check the voltage at the fuse location I gave you while under load? Maybe the power is bad from that point. Link to comment Share on other sites More sharing options...
lmdew Posted July 14, 2007 Author Share Posted July 14, 2007 Both Fuses in the AC Relay holder are good. What I think is the AC Relay holder is in the engine compartment, Drivers side in the fuse/relay box. There is a mount for the AC Relay, Fan and Sub Fan. At the front, there are 2 15 amp fuses. Am I in the wrong place? Link to comment Share on other sites More sharing options...
svxpert Posted July 14, 2007 Share Posted July 14, 2007 is the sysytem charged with refrigerant? Link to comment Share on other sites More sharing options...
Cougar Posted July 14, 2007 Share Posted July 14, 2007 Both Fuses in the AC Relay holder are good. What I think is the AC Relay holder is in the engine compartment, Drivers side in the fuse/relay box. There is a mount for the AC Relay, Fan and Sub Fan. At the front, there are 2 15 amp fuses. Am I in the wrong place? I think you are in the right place. My info shows there is 3 wires going to the AC mode control box. There are 2 others for the light in it. The switch is fed 12 volts and it looks to me that the other two contacts may be something like a high/low setting. The power input is a red/blk wire on pin 2. The other two contacts should be tieing to that lead I think so if you don't have 12 volts there then the switch is bad. Link to comment Share on other sites More sharing options...
lmdew Posted July 14, 2007 Author Share Posted July 14, 2007 That's what I was thinking. I pulled the switch, destroyed it getting it out and put in a good one I had. Same results. I have power at the AC Switch both into the switch and out when the main control plug is unplugged. When I plug the main connector back in, the output voltage dropps to 0. I have to get the correct wiring diagram for this car. I have the same diagram you have from the wire codes you've given me and none of the wire colors match the car. Strange! Thanks for taking the time to help on this. Larry Link to comment Share on other sites More sharing options...
OB99W Posted July 14, 2007 Share Posted July 14, 2007 I don't seem to have the correct wiring diagram either, but I can provide some typical info that may be helpful. 1) In A/C mode, the radiator fans are controlled via relays by the ECU; if the ECU detects certain A/C problems, it won't turn the fans on. 2) The refrigerant pressure switch isn't the only thing that can cause the compressor relay coil circuit to not be completed. Have you checked the evaporator thermo switch, or wiring to it? It usually only comes into play when the evaporator temp gets out of range, but it can fail and cause the A/C relay coil circuit to be open even if the evap temp is normal. Link to comment Share on other sites More sharing options...
Cougar Posted July 14, 2007 Share Posted July 14, 2007 When I plug the main connector back in, the output voltage drops to 0. Are you saying the input wire is staying at 12 volts when the plug is connected? Just the other two wires are dropping to zero. If this is so then this module is more than a simple switch. EDIT After looking at the drawing again it looks to me that the switch is working as it should be but since there isn't enough details on the modules I can't tell for sure. One thing obvious on pin 3 is, it goes to the fan switch, which ties to ground. So we know that is ok. The AC relay coil gets power from fuse 15 through the evaporation/thermo switch. You should have power from the fuse on pin 3 there. Have you checked that? Link to comment Share on other sites More sharing options...
lmdew Posted July 15, 2007 Author Share Posted July 15, 2007 Not yet, this has moved to the back burner for a few weeks. I did find the same car in a yard today and pulled the evap switch, the control panel and all the relays. When I get back to it, I'll give them a shot one at a time. Thanks for the help. Larry Link to comment Share on other sites More sharing options...
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