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Hey all,
I’ve recently deleted my AC system from my GS as it is not going to be a daily driver mostly weekend drives and track. I’m looking to continue to use the stock radiator fan and AC condenser fan. However by the way it’s wired, depending on AC system pressure and coolant temp, the fans turn on or off. Since deleting the entire AC system, the fans stay on while ignition is on. I want the fans to turn on based off of coolant temp only. Does anyone know how I can do this? Car is running a EMU Black with PnP harness, and stock ECU for trans control. Main question is how can I bypass the AC single switch so that the fans turn on or off based off of coolant temp only? Below I have attached the wiring diagram for this system. Any help would be appreciated.
If the pressure switch fails this causes the fans to run all the time this is by design. Bypass the switch with a jumper wire and your fans should work normally.
If the pressure switch fails this causes the fans to run all the time this is by design. Bypass the switch with a jumper wire and your fans should work normally.
I tried using a jumper wire to bypass the ac single pressure switch but it didn’t seem to do anything. I thought that would work, I think I’m missing something here
Try this, ground the wire which goes to the relay (see image) the fans should stop. Report back.
yes that made the fans stop but my car can’t get up to a high enough temp outside as it’s about 10° outside so I can’t tell if the fans are going to switch on or not when it gets up to the set 194°f for the fans to kick on
Next step is check to see if the water temp switch (in radiator) is grounded when the engine is cold. It does sound like this has gone bad or maybe a wiring issue. FYI the circuit is a fail safe design if the rad switch and/or AC pressure switch are bad (as well as wiring) the fans always run. This way you won't cook your engine.
Next step is check to see if the water temp switch (in radiator) is grounded when the engine is cold. It does sound like this has gone bad or maybe a wiring issue. FYI the circuit is a fail safe design if the rad switch and/or AC pressure switch are bad (as well as wiring) the fans always run. This way you won't cook your engine.
after looking at the wiring diagram this morning, fan relay 3 gets its power from the ac comp. Relay and that relay gets its power signal from the ECU. So when the ignition is in the on position relay 1 should be turned off while relay 2 is turned on from there current would travel to relay 3 but if there is no power signal from the ECU since the ECU is no longer receiving any signal from the clutch and lock sensor or the ac double pressure switch, relay 3 would remain off. If 3 is off then the logic gate stays disconnected in turn sending no current through the closed logic gate of relay 2
at least this is how I’m understanding it when I look at the wiring diagram for the automatic air conditioner and the radiator fan wiring diagram. I may be wrong. I’m going to try to bypass relay 3 and see if that changes anything
So the fan on the left side (drivers side) uses a temp switch to turn off and on and the right fan is the auxiliary which turns on when the a/c is switched on. If you want them to both work off the temp switch, that’s easy, just find the 2 wires coming off the auxiliary fan, u need to just ground the ground and then run the + over to the + wire on the main fan, just tap into it so that they both come on when the temp sensor activates them. But I really don’t think u need the auxiliary fan anymore. I would just disconnect it and confirm the main fan is working correctly, keep an eye on the temp gauge in the summer time. If you need both fans, then u can buy a whole circuit for an aftermarket fan from an auto parts store, it will have a temp sensor, relay, and adjustable controller to set when the auxiliary fan operates. The whole kit only costs about $15
AC Pressure switch bypass
