Jim Hughes 0 Posted June 29, 2009 Hello, The above comes on when I switch off the ignition and would stay on till it drained the battery. I have dissconected all the temp sensors and reconnected to suit in an effort to eliminate a faulty one, the fan stays off when the ignition is on and cuts in when the engine is too hot. but as you will gather as the fan is disconnected most of the time, I can't carry on like this in hot weather! I have ruled out the thermo/time switch on the radiator as when you unplug that it makes no differance to the problem, any advice would be very welcome. My car is an 91-92 J plate 1.8 16v :shrug: Oh, BTW I think it could be a short, the Battery drains after a a few day of non use. Quote Share this post Link to post Share on other sites
rossb 0 Posted June 29, 2009 mine had a similar problem, but the fan would not cut in when the car was running as well. a new rad switch sorted it. :thumb right: Quote Share this post Link to post Share on other sites
colinstubbs 0 Posted June 29, 2009 Front of the head, end by the oil filler cap there is a yellow(ish :lol: ) sensor, looking like a big nut with a spade connector on the top. This controls fan run-on for 10 mins after the ignition is turned off. If it has shorted inside/failed some other way the fan will just run all the time or not at all. If you disconnect the spade terminal the fan should stop, if you then short it onto the head the fan should start again, if the fans runs with the sensor disconnected it's not that sensor at fault. If the fan runs on after the 10 mins and stops when the sensor is disconnected the sensor is at fault. They're £10-15 IIRC from the Stealers and the number is stamped on it! fan run on sensor (Large).jpg[/attachment:183y772h] Quote Share this post Link to post Share on other sites
Jim Hughes 0 Posted June 30, 2009 Front of the head, end by the oil filler cap there is a yellow(ish :lol: ) sensor, looking like a big nut with a spade connector on the top. This controls fan run-on for 10 mins after the ignition is turned off. If it has shorted inside/failed some other way the fan will just run all the time or not at all. If you disconnect the spade terminal the fan should stop, if you then short it onto the head the fan should start again, if the fans runs with the sensor disconnected it's not that sensor at fault. If the fan runs on after the 10 mins and stops when the sensor is disconnected the sensor is at fault. They're £10-15 IIRC from the Stealers and the number is stamped on it! fan run on sensor (Large).jpg[/attachment:3ef6csut] Thanks for the reply Colin, I replaced that sensor first thing when this problem started. It didn't change a thing. If you disconnect the wire/spade connection the fan stops. If you then short the wire to the head the fan starts, likewise if you reconnect the spade connection. Also if you disconnect the battery ie the earth then reconnect the fan does not run, It only starts to run after the ignition switch has been turned to starting position and then returned to the off position. :shrug: Quote Share this post Link to post Share on other sites
Jim Hughes 0 Posted June 30, 2009 Think I could have had that eureka moment :cheers: The sensors are colour coded right? The one I replaced was so old and knackered I guessed it was the black type, You could not tell the colour, the only thing I knew was when I wiggled the spade conection the fan cut in and off! I ordered a new black one, the problem stayed. They are wax filled - correct? resistance issue. If it is supposed to be yellow the tollerence will be different from a black one right :cuckoo: Quote Share this post Link to post Share on other sites
colinstubbs 0 Posted July 3, 2009 I think you could be right there I'll have a look at it to see if I can get a number off it.... 1919195210 or 1919195218 i think. :salute: Quote Share this post Link to post Share on other sites
blue95 0 Posted July 3, 2009 How long should the fan stay on if you just short it, i.e. just connect the wire to the body? Does the relay have some kind of timer? Quote Share this post Link to post Share on other sites
colinstubbs 0 Posted July 3, 2009 It should be around 10 mins, the yellow sensor just turns the fan on/off according to the heat of the head during that period. I've always wondered but never asked where the hell the fan controller/relay(s) is/are on the 1.8 valvers? On the VRs and 2.0 valvers at least they are obvious, on that bracket in front of the coolant reservoir! I assume they control the time. The yellow sensor is just a temperature sensitive earth and acts just like earthing the wire on the head as long as it gets power. Quote Share this post Link to post Share on other sites
blue95 0 Posted July 3, 2009 they hid the relays away again on the late valvers LOL Quote Share this post Link to post Share on other sites
RDH 0 Posted July 5, 2009 Sorry to kindof hijack thread, do late valvers have a fan control module (the one near the coolant bottle), my 94 does not have one, and the fan only works on lower speed. TIA Rich Quote Share this post Link to post Share on other sites
Jim Hughes 0 Posted July 13, 2009 Front of the head, end by the oil filler cap there is a yellow(ish :lol: ) sensor, looking like a big nut with a spade connector on the top. This controls fan run-on for 10 mins after the ignition is turned off. If it has shorted inside/failed some other way the fan will just run all the time or not at all. If you disconnect the spade terminal the fan should stop, if you then short it onto the head the fan should start again, if the fans runs with the sensor disconnected it's not that sensor at fault. If the fan runs on after the 10 mins and stops when the sensor is disconnected the sensor is at fault. They're £10-15 IIRC from the Stealers and the number is stamped on it! fan run on sensor (Large).jpg[/attachment:2ity7rhr] Many many thanks for your superb advice Colin, I replaced this sensor today with the correct "Yellow one" the problem with the cooling fan is solved. I owe you a pint fella :cheers: Quote Share this post Link to post Share on other sites
colinstubbs 0 Posted July 13, 2009 Glad too have been of service! That's what the forum is all about! 8) Quote Share this post Link to post Share on other sites
FenderSi 0 Posted October 24, 2009 Just thought I'd add another thanks. Had a problem with my fan after having just replaced the rocker box cover gaskets - was thinking it was a totally new issue but I think I must have just given the run-on sensor a bit of a wiggle when putting the bolt back through the head. Thread saved me going out and buying a new thermostat switch only to find out it wasn't even that! Gotta love the corrado forums! Thanks again! Quote Share this post Link to post Share on other sites
colinstubbs 0 Posted October 25, 2009 :clap: Another satisfied customer :clap: oooh yeah 8) 8) 8) Quote Share this post Link to post Share on other sites
