MJam86 Posted November 25, 2013 Share Posted November 25, 2013 Hey guys I'm kinda new around here ive been lurking for a while. I have learned a lot through here and frequently spend my 12 hour shift just reading random things. I recently bought a 88 comanche eliminator. I got it up and running, cleaned it up and even realized I have a D44 rear end. As soon as I turn the key on my electric fan turns on. I didnt think much of it but after I finished repairs and a general tune up I took it out and ran the crap outta it to see if id get any issues. I noticed my temperature for the most part lingers around 180ish. I did some reading and I found this http://jeep.zerok.ru/index.php?page=100. I searched and havent seen anyone else with the issue I'm having (my fan basically always runs where the searches ive found they normally don't work.) I kinda am leaning towards maybe my temp probe by lower radiator house is messed up and stuck above 190 causing the fan to immediately kick on. I would think if the relay was bad it wouldnt kick on. So, has anyone else had this issue and how did you fix it? I am thinking I may just bypass the relay and run it off of a switch so I can control the fan "manually" so to speak. No I don't have defrost or a/c on either so I know thats not the issue. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted November 25, 2013 Share Posted November 25, 2013 For a quick test to see if the temp switch is bad just unplug it. If the fan turns off, there's your answer. If it continues to run, you've got problems else where. Link to comment Share on other sites More sharing options...
MJam86 Posted November 29, 2013 Author Share Posted November 29, 2013 Yea I realized that. I unplugged the switch and it still ran. I'm not sure if it would still run if it didn't sense a switch. For now I'm going to just going to run an aux switch. I ran it without the electric fan and the highest I got was about 200 degrees so the electric fan is not needed really at least not yet. Link to comment Share on other sites More sharing options...
Eagle Posted November 29, 2013 Share Posted November 29, 2013 Yea I realized that. I unplugged the switch and it still ran. I'm not sure if it would still run if it didn't sense a switch. For now I'm going to just going to run an aux switch. I ran it without the electric fan and the highest I got was about 200 degrees so the electric fan is not needed really at least not yet. The thermal sensor triggers a relay. More than likely the relay is stuck. Link to comment Share on other sites More sharing options...
cruiser54 Posted November 29, 2013 Share Posted November 29, 2013 Yea I realized that. I unplugged the switch and it still ran. I'm not sure if it would still run if it didn't sense a switch. For now I'm going to just going to run an aux switch. I ran it without the electric fan and the highest I got was about 200 degrees so the electric fan is not needed really at least not yet. The thermal sensor triggers a relay. More than likely the relay is stuck Isn't that relay right there on the driver side inner fender?. Link to comment Share on other sites More sharing options...
yxmj Posted November 29, 2013 Share Posted November 29, 2013 Yea I realized that. I unplugged the switch and it still ran. I'm not sure if it would still run if it didn't sense a switch. For now I'm going to just going to run an aux switch. I ran it without the electric fan and the highest I got was about 200 degrees so the electric fan is not needed really at least not yet. The thermal sensor triggers a relay. More than likely the relay is stuck Isn't that relay right there on the driver side inner fender?. If your relay is there that would be an easy solution......figure out the trigger wire ftom the sensor....replace that with a lead that runs to a toggle in the cab....the other side of the toggle run to an accessory output on your fuse panel....that would give you manual control; from the cab that turns off with your ignition......or just add a small relay to the fender wired the same way Link to comment Share on other sites More sharing options...
MJam86 Posted November 29, 2013 Author Share Posted November 29, 2013 The link I posted before states left inner fender panel. I assume that is passenger side. Link to comment Share on other sites More sharing options...
87MJTIM Posted November 29, 2013 Share Posted November 29, 2013 Left is driver's side, right is passenger's side. Just remember as you sit in the vehicle, facing forward, which side is you left and which is your right. Link to comment Share on other sites More sharing options...
Eagle Posted November 30, 2013 Share Posted November 30, 2013 Do NOT try to wire the fan directly to a toggle switch, bypassing the relay. They put a relay in the circuit for a reason. I don't know what the amperage is on the Renix aux fan but on my wife's 2000 XJ it's on a 40-amp fuse -- and we've seen it blow that fuse. If you run it directly off a switch, I hope you own stock in a company that makes toggle switches, because you're going to be buying a lot of them. Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 30, 2013 Share Posted November 30, 2013 Normally the 5-blade aux fans used in the Renix pull a max on 20A on startup, but that's for a fairly new fan. A 20+ year old fan with rusty bearings and questionable wiring can easily pull 10A more. The newer 10-blade fans on the 97 and up XJs normally pull about 10A more than the Renix fans, but they move more CFMs of air too. Link to comment Share on other sites More sharing options...
MJam86 Posted November 30, 2013 Author Share Posted November 30, 2013 Ahh I assumed the orientation was as I was looking at the engine thanks for the heads up! Link to comment Share on other sites More sharing options...
MJam86 Posted November 30, 2013 Author Share Posted November 30, 2013 I wasnt planning on it, I work at a power plant so I get all my electrical stuff for free anyways. Except LEDs :-( Link to comment Share on other sites More sharing options...
Tactical Bacon Posted November 30, 2013 Share Posted November 30, 2013 Check to make sure they didn't ground out the fan control relay. I had that going on with my Firebird. They ran a wire from the relay ground blade to a body ground so the fans always ran. Link to comment Share on other sites More sharing options...
MJam86 Posted December 16, 2013 Author Share Posted December 16, 2013 Left is driver's side, right is passenger's side. Just remember as you sit in the vehicle, facing forward, which side is you left and which is your right. Still not sure about this. The relay is definitely on the passenger side. Link to comment Share on other sites More sharing options...
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