Magnesiac Posted January 30, 2013 Report Share Posted January 30, 2013 First off I did a lot of searching in this forum before asking this. I did not come across a post where someone was having the same issue as I am having so I am making this post to hopefully get a fresh perspective as to what could be my issue. I do have the FSM but the electrical volume is very confusing to me and hasn't helped me diagnose the problem. Maybe I need someone to dumb it down for me, lol. Thanks for any and all help. I bought this '88 Quest stripped down to just the shell and wiring. I rebuilt this car over the last several years. Since I installed the new engine and hooked up the cooling system I have had a problem where the primary cooling fan will not engage. I even went ahead and grounded out the thermosensor wiring at the bottom of the radiator and that has my secondary fan working fine as well as the AC condensor fan but the primary fan will still not engage. I thought, maybe it's a bad fan motor, and installed another... Same issue. Can anyone give me some ideas on what to check and look for? Is it possible to hook a relay up incorrectly and cause an issue like this? I am a bit stumped. Link to comment Share on other sites More sharing options...
Crazy larry Posted January 30, 2013 Report Share Posted January 30, 2013 my guess is both fans are Bad. FSM has a diagram on how to test jumper the fans.. I do think that even if they turn on they could be running slow and not moving enough air. that could be caused by a bad relay, (weak connection) bad ground, or bad wireing. lots of things can cause overheating, Link to comment Share on other sites More sharing options...
ucw458 Posted January 30, 2013 Report Share Posted January 30, 2013 The 2 relays shrouded in rubber on the same bracket next to the air filter are the cooling fan relays. Check to see if they have power, are missing, have hacked wiring or are just bad relays. Grounding the wire running to the thermoswitch below the fan will turn them on. Link to comment Share on other sites More sharing options...
Magnesiac Posted January 30, 2013 Author Report Share Posted January 30, 2013 (edited) The 2 relays shrouded in rubber on the same bracket next to the air filter are the cooling fan relays. Check to see if they have power, are missing, have hacked wiring or are just bad relays. Grounding the wire running to the thermoswitch below the fan will turn them on. Cool. I will check those out. Thank You very much. BIG help. Edited January 30, 2013 by Magnesiac Link to comment Share on other sites More sharing options...
Magnesiac Posted February 7, 2013 Author Report Share Posted February 7, 2013 Thanks to UCW458. It was those relays. Good call. I hadn't plugged the primary one in far enough.... Dumb mistake. Thanks for the help with that. Now I am not out of troubled waters quite yet though.... Now the primary fan comes on as soon as I hook up the battery. No key in the ignition. I even disconnected the wire that goes to the thermosensor at bottom of radiator... Any idea what would cause this? Link to comment Share on other sites More sharing options...
ucw458 Posted February 7, 2013 Report Share Posted February 7, 2013 Unplug both sensors and see if the fan turns off. If it does then that sensor is bad and both sensors may be wired together. Also switch the relays between the 2 fans. If the secondary comes on after switching the relays then you know the relay is stuck on and should be replaced. If those don't do it check for shorts or hacked wiring. The 2 thermoswitch wires should have no continuity to ground when both are unplugged. If they do you have a short somewhere. Link to comment Share on other sites More sharing options...
importwarrior Posted February 8, 2013 Report Share Posted February 8, 2013 (edited) i thought the 2 relays covered in rubber next to the air filter are for the fog lights???? might want to check this link out. http://starquest.i-x.net/viewtopic.php?t=1067 http://starquest.i-x.net/viewtopic.php?t=1097 Edited February 8, 2013 by importwarrior Link to comment Share on other sites More sharing options...
ucw458 Posted February 8, 2013 Report Share Posted February 8, 2013 i thought the 2 relays covered in rubber next to the air filter are for the fog lights???? There are 3 relays there. The 2 on the same bracket are for the rad fans. The single one is for the fog lights. Link to comment Share on other sites More sharing options...
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