importwarrior Posted July 26, 2015 Report Share Posted July 26, 2015 AC Pusher fan relay wire colors please. I don't have Ac have not had AC in years. Trying to help a friend that has AC The Pusher fan does not come on when AC is turned on. Thought it should. The fan works fine directly connected. It just does not come on when AC is on. Like to jumper the delay to see if it triggers it to come on I just don't know what wire to jump. The AC works fine besides the front Pusher fan. Link to comment Share on other sites More sharing options...
mikec Posted July 26, 2015 Report Share Posted July 26, 2015 The pusher fan does not automatically run when the a/c is on... it turns on only if the refrigerant pressure gets pretty high - indicative of a very hot day. Look for a small connector with black and black+yellow wires on the harness side, it'll be a sensor attached to the a/c plumbing near the receiver/dryer. That's the "high pressure" switch. Unplug the connector and jumper the harness connectors. That should make the pusher fan and engine-side secondary fan engage. The relay triggered by this sensor has blue+black, black+yullow, black, and blue+yellow wires. Relay A-24, one of the relays hanging on that bracket by the ignition coil. The fan configuration on StarQuests has two separate functions:* engine cooling* a/c operationThere are separate sensors feeding separate relays for each function. For engine cooling:There are temp sensors on the bottom of the radiator; each sensor triggers a cooling fan relay (located by the air cleaner) to run the fan above it. However, a wire connection from the secondary fan (smaller fan) happens to cross over into the air conditioner's high pressure sensor so it triggers the a/c pusher fan relay & pusher fan as well. Thus, when the water temps get hot enough to trigger the secondary fan (near 3/4 on the dash guage) both the secondary and pusher fan should engage. For a/c operation:The climate control computer has its own relays to run the primary and secondary fans. They are basically in parallel with the cooling fan relays - e.g. either the cooling fan relays OR the climate control relays can feed +12volts to the fans. Sometimes both relays are engaged at the same time... just means the fan has two relays giving it 12 volts... either way, it runs normally. That a/c refrigerant pressure sensor feeds the A-24 relay to kick in the pusher fan only on very hot days (otherwise the a/c could over-cool leading to icing in the evaporator box and thus excessive on-off cycling). Because of that extra "if overheating" wire in the engine cooling function, this sensor will also trigger the secondary engine fan via its cooling fan relay... which should already have been running from the a/c computer's relay controlling that fan anyway. mike c. Link to comment Share on other sites More sharing options...
importwarrior Posted July 26, 2015 Author Report Share Posted July 26, 2015 Thanks so much Mike.Greatly appreciated.Everything on the AC is great.I was worng, I thought it automatically came on when theAC was switched on. This particular car does not have a second fan original owner, SLY DOG might have removed the second fan. The primary fan is stout and works great problem is that the temp creeps up when AC is on.Wondering what to do to provide beter fan cooling.. also no room for a second on the radiator. Thanks again By the way. This car is an 86 mint condition. Link to comment Share on other sites More sharing options...
wrngwae Posted July 27, 2015 Report Share Posted July 27, 2015 http://i1170.photobucket.com/albums/r521/wrngwae/Mobile%20Uploads/image_15.jpghttp://i1170.photobucket.com/albums/r521/wrngwae/Mobile%20Uploads/image_16.jpg I have the same issue. I can jumper the fan and it works. And all relays test good. What I don't understand is what they mean by changing the Ecu? Is there a Potentiometer that you adjust for fan turn on? Link to comment Share on other sites More sharing options...
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