markt Posted January 31, 2006 Report Share Posted January 31, 2006 Hi All I keep getting a fan fail light every time my fans kick in. At least the dash light now works. They seem to want to operate at the correct temperature, so no problems there. All three work for a few seconds, then two trip, middle and right hand side. Otter Switch trips like it's supposed to, re-set, all three work again for a few seconds then two cut out. All three seem to run fine if the temperature sender unit is bridged. Had them running for hours just to see what would happen, nothing except I drained the battery. No binding, fouling on the cowlings, loose wires or bearing rattles etc... My mechanic did the same sort of test and no problems, Sods Law. He reckons I'm talking bollocks. Car handles temperature okay in traffic, but I can do without white knuckle rides giving the temperature gauge more attention than the road ahead... This is proving to be a rather elusive fault so any ideas would be welcome. Thanks in advance for any suggestions - Mark Quote Link to comment Share on other sites More sharing options...
Simon350S Posted January 31, 2006 Report Share Posted January 31, 2006 Not had chance to look at my circuit diagrams as they are all packed in storage.. I may be talking bollox but have you tried swapping/changing the fan relay and/or the thermostat?? If they are on their way out and rapidly turning the fans on/off in quick succesion or something like that then that could cause the trip to well... trip due to the constant high current surge???? As I said I may be talking bollox but its gotta be worth a try, afterall youve tested the fans on manual and proved they are working, and they are only cheap parts Quote Chunky Lover Link to comment Share on other sites More sharing options...
matk Posted January 31, 2006 Report Share Posted January 31, 2006 Complete long shot.......... I would check the fan wiring and make sure there on the same relay. UK market cars ran 2 fans with a space for the third which was inserted for hot climates (USA etc). Maybe someone has put in the third fan on a new circuit and this is working fine but the original relay is faulty under load? As I said long shot but if you have faults with different fans says to me they must be on different circuits. Apologies if I'm talking bollox! Regards Mat Kutub 1979 S2 Quote Regards Mat Link to comment Share on other sites More sharing options...
markt Posted February 1, 2006 Author Report Share Posted February 1, 2006 Thanks for the replies... Will replace the relay (If I can ID the thing without a wiring diagam or manual) and see if that makes any difference. BTW my car is a domestic (UK) spec. So if an additional fan has been wired in at some stage, past experience says I will be ripping out wires and re-doing. How the car hasn't caught fire with the bodged dodgy wiring is beyond me... Cheers - Mark Quote Link to comment Share on other sites More sharing options...
WayneB Posted February 1, 2006 Report Share Posted February 1, 2006 When the fan motors are getting worn out they will use more current to operate and trip the relay. Did you try disconecting the fans one at a time to see which one trips the relay? If you want I will look at my wiring diagrams when I get time, to see the diffrences between UK and Federal/Hot Climate fan setup Quote Link to comment Share on other sites More sharing options...
markt Posted February 2, 2006 Author Report Share Posted February 2, 2006 Hi Wayne Fans have just been overhauled with new bearings. Was a very slight rumble from one of them. I think I'm gonna get the front of the car completely re-wired. Too much stuff has been butchered in the past. As I mentioned, my car is a Domestic/UK spec. Don't see 30 degree+ heat happening in Hethal. Time to get things sorted out properly. If you could send me something on the Hot Climate set-up, much humble appreciation etc... Thanks - Mark Quote Link to comment Share on other sites More sharing options...
matk Posted February 2, 2006 Report Share Posted February 2, 2006 Rewired mine last year using new relays and unused fuse in fusebox. As long as your otter switch works is an easy job. Regards Mat Kutub 1979 S2 Quote Regards Mat Link to comment Share on other sites More sharing options...
f1karting Posted February 2, 2006 Report Share Posted February 2, 2006 (edited) Hi All All three seem to run fine if the temperature sender unit is bridged. Had them running for hours just to see what would happen, nothing except I drained the battery. No binding, fouling on the cowlings, loose wires or bearing rattles etc... <{POST_SNAPBACK}> This seems to be a key to the problem somehow... maybe its the sender gone foul. Did you get any overheated wires or components on your enduro run? I believe those fans will draw about 8 to 10 amps each, so maybe the relay rating is too low, but then if that were a problem, then you would think the relay would weld itself in the on position??? What Wayne said about the draw makes sense, but with good motors, maybe the thermal trips are weak and cant manage the current. I have a wiring diagram I can post if you like..J Edited February 2, 2006 by f1karting Quote If you set no goals you shall surely reach them.. Link to comment Share on other sites More sharing options...
WayneB Posted February 2, 2006 Report Share Posted February 2, 2006 (edited) Heres the wiring diagrams as promised This one is for Domestic/ROW (with thermal trip) This one is Federal (no thermal trip, warning light instead) If your Thermal trip keeps malfunctioning. you might do well to get rid of it and go with the Federal setup Edited February 2, 2006 by WayneB Quote Link to comment Share on other sites More sharing options...
markt Posted February 3, 2006 Author Report Share Posted February 3, 2006 (edited) Thanks for this Wayne Will give me something to do tomorrow. Big thank you Mat, Jan & Simon for all the suggestions. Let you all know Monday. Have a good weekend. Cheers - Mark Edited February 3, 2006 by markt Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.