oxfordpaul 0 Posted August 28, 2007 Hi all, I've read for hours the posts on here but haven't found the answer to my problem. The fans don't cut in till about 105 plus which is too late and I would say certainly stage 2. At about 100 the fans don't run unless I turn the engine off - then they cut in. I have tested the electrics and found the following:- 1. When bridging the wires for the thermoswitch I have found speed 2 works with the ignition on but not with it off. This is the red wire with the red and black wire. 2. Bridging the main feed (red wire) with the red/white (speed 1) wire makes the bulb light up on my tester with the ignition on and off but the fan does not run either with or without ignition. 3. Bridging the brown/red and brown/green (diagonal opposite) on yellow multiplug operates the fan at speed 1 with the ignition off as it should. So it's clear speed 1 works with the engine off but why won't it work with the engine on? PLEASE NOTE I've done all these tests with the engine cold. Is there another sensor somewhere that needs bridging to fool the thermoswitch wiring into thinking it's warm for the fans to run? Share this post Link to post Share on other sites
oxfordpaul 0 Posted August 29, 2007 Bump, please anyone? Share this post Link to post Share on other sites
Crasher 3 Posted August 29, 2007 Has the car got Diavia air con? I would change the fan control unit first but have you checked the strip fuse on the fan control unit? Share this post Link to post Share on other sites
oxfordpaul 0 Posted August 29, 2007 Hi Crasher, no aircon. also have just tried bridging the terminals again with a plain piece of wire rather than my bulb screwdriver and the low speed works! so the cuurent for the bulb must have sapped the power instead? Anyhow I did this with the fan controller totally disconnected and the fans still ran (speed 1 only). Therefore does the controller have any effect on speed one and if so what? I reconnected all and let it run to temp. The fan cuts in just after 93 or so but only for a few seconds and then stops. The guage continues to rise to about 106 and then they cut in again but it sounds like the same speed as the first time. They then cut in and out but the temp stays at just under 110. Also I noticed that my aux pump is on with the ignition but off when the ignition is off even if the engine is hot - I thought it was supposed to run on for a few minutes? Does the fan controller run this part too? Share this post Link to post Share on other sites
Crasher 3 Posted August 29, 2007 Yes, the fan controller is responsible for the pump as well, the low rating fuse of the two blades fuses. Have you checked the strip fuse? Share this post Link to post Share on other sites
oxfordpaul 0 Posted August 29, 2007 Hi, the fuses all look fine in the fan controller module. The aux pump does work and I've just discovered it shouldn't stay on after the negine is shut down unless the coolant is 107 degrees or more so that may explain that. So I'm still stuck on one question - does anything other than the rad switch affect the on or off nature of the fans? If not then i must have a faulty switch (even though it's new) or a faulty guage (but I doubt this as it reads a perfect 90 when travelling at speed). Share this post Link to post Share on other sites
oxfordpaul 0 Posted September 3, 2007 Update! I've bought a new fan controller and it's made no difference to the temp at which the fans come on. In fact, the fans work exactly the same whether the controller is plugged in or not. However, one thing that does now work is the aux pump after the engine is switched off. It used to only work with the ignition but now it stays on after the engine is switched off (this was when it was hot, about 100 degrees). HOWEVER, the fans did not come on, only the aux pump. I thought they were supposed to run at the same time as the run-on circuit? Therefore does this again point to my speed 1 not working? Also when buying the controller they also showed me a relay that is part of the fan speed circuit. Does anyone know if this controls speed 1 and 2? Or have I simply got a duff rad switch, faulty guage or dodgy fans that are seizing up and therefore not working with the 6v supplied for speed 1? Share this post Link to post Share on other sites
fla 9 Posted September 5, 2007 I'd be intersted in comments to this issue - on my car, when the cooling fan trips in it also starts the aircon compressor, which doesnt make any sense. Share this post Link to post Share on other sites
Kevin Bacon 5 Posted September 6, 2007 The fans aren't SUPPOSED to come on with the pump, they will only if required. Speed 1 is autonomous of the fan controller and runs direct from the battery, triggered by the radiator switch (red wire). Speed 2 is the black/red wire from the rad switch and is run via ignition / fan controller only. Locking as this has been covered countless times. Share this post Link to post Share on other sites
