Alex_G60_Fanatic 0 Posted August 19, 2011 I'm sorry for the laymen tech-speak but I'll try to be as detailed as possible... I've just got my car back from the MOT centre... They couldn't conduct the MOT because the fan wouldn't engage and the car was over heating. The garage apparently tried to connect the fan directly to the coil but after doing this the battery wouldn't start the car (it's a new battery though, it should work...) Prior to sending it to the garage the following was done to the car: (see pic) [ATTACH=CONFIG]48718[/ATTACH] The radiator was replaced with a 6 month old second hand replacement. The Two temperature sensors 12 &13 above where both replaced with new OEM parts. The fan was hooked up and tested with a battery. I placed a current across the fan terminal and the fan spun nice so the motor is fine. After testing the car myself on the drive and finding the fan not working I asked the garage to replace the fan switch in the radiator for a new one (unsure where they got the switch but I imagine it is a cheep one from Browns/Dingbro's/Autocar Parts ect. The only other electrical work I have done on the car is fit an external uprated head light loom (from Kur2ly on here) I've checked the fuse box... they're all fine (although I did fix my stereo while I was in there so that's a bonus at least!) SO.... What's wrong with my Fan? Dodgy earth maybe? where is the earth to the fan? HELP :shrug: P.S. I have a multimeter but I'm a electrical retard and wires scare me... If there is anyone near Dundee who could help I would be grateful! Otherwise just make sure you talk slow and explain as you would to a trained chimp holding a blunt instrument.... :thumbleft: Quote Share this post Link to post Share on other sites
dannyboy 0 Posted August 19, 2011 alex have you checked the fan switch in the radiator?its what turns the fan on.Number 9 on the diagram.has three pins for two stage fan. Quote Share this post Link to post Share on other sites
Alex_G60_Fanatic 0 Posted August 19, 2011 alex have you checked the fan switch in the radiator?its what turns the fan on.Number 9 on the diagram.has three pins for two stage fan. Yes dude... Number 4 in the first post. The garage put a new one in for me. Looks fine... [ATTACH]48720[/ATTACH] Been looking in my Bently manual and spotted the above. It says "disconnect thermoswitch and touch to ground" Does it mean touch the thermoswitch to earth with the wire connected to it or what?? How do I touch it to ground? Could this be the problem?? Quote Share this post Link to post Share on other sites
dannyboy 0 Posted August 19, 2011 thats an over-run switch for the fan when the engine bay is too hot.If you touch that single connector to ground the fan should come on! ---------- Post added at 07:31 PM ---------- Previous post was at 07:29 PM ---------- sorry i meant disconnect the wire and touch the wire on the engine and the fan should come on Quote Share this post Link to post Share on other sites
Alex_G60_Fanatic 0 Posted August 19, 2011 thats an over-run switch for the fan when the engine bay is too hot.If you touch that single connector to ground the fan should come on! ---------- Post added at 07:31 PM ---------- Previous post was at 07:29 PM ---------- sorry i meant disconnect the wire and touch the wire on the engine and the fan should come on Well, I just tried that and it didn't come on.... Touched the wire to the head and no fan.... Now what? Thing is, how does that test the thermoswitch? Surely that just tests the wiring?? Quote Share this post Link to post Share on other sites
dannyboy 0 Posted August 19, 2011 it says replace the switch on the rad! Have you got a multimeter? turn it to volts and test the pins on the harness of the rad switch you should get 12 volts ---------- Post added at 07:56 PM ---------- Previous post was at 07:54 PM ---------- with ignition on. Quote Share this post Link to post Share on other sites
Alex_G60_Fanatic 0 Posted August 19, 2011 it says replace the switch on the rad! Have you got a multimeter? turn it to volts and test the pins on the harness of the rad switch you should get 12 volts ---------- Post added at 07:56 PM ---------- Previous post was at 07:54 PM ---------- with ignition on. It said replace switch, didn't say anything about rad switch... I thought it meant thermoswitch... :/ Good thinking about that loom to the radiator switch though, I'll try that tomorrow. Cheers! Quote Share this post Link to post Share on other sites
Alex_G60_Fanatic 0 Posted August 19, 2011 Been up late reading my Bentley manual. As far as I can tell the wiring diagram shows the earth for the fan is the same as the head lights!!! Does that mean my external headlight loom could be messing with my fan??? --- - Sent from my iPhone you lemon! Quote Share this post Link to post Share on other sites
dannyboy 0 Posted August 20, 2011 very much doubt head loom would cause that unless the weld is broken inside the harness.and they hefty wires too.The fan has its own fuse 30 amp. I spent this morning looking over the wiring diagram for you and its not really complicated. The thermoswitch on the cylinder head has a control unit that does excatly the same as the thermoswitch on the radiator so it points out to that you have a supply problem rather than a sensor problem.Funny enough the connector on the Fusebox is on the same one as the headlight one as you said . Its A1 (yellow,theres two!) pin 5 and wire is 2.5mm red. check for loose wires or connector.I think the headlight loom can still work with one of the connectors disconnected! Quote Share this post Link to post Share on other sites
