kyepan 291 Posted February 2, 2008 Hiya, My cooling fan is not cutting in. fan runs off a 12v battery fine, get 5v and then 14 v across the fan feed connector when the car is warm and hot bridging the switch does not get the fan to cut in, get good ground to one wire to the switch however get no voltage across the switch. does that mean that no voltage is getting back from the fan supply to the switch? any help appreciated. cheers J Share this post Link to post Share on other sites
kyepan 291 Posted February 2, 2008 (edited) I checked all the 25a fuses in the glove box fuse board and they looked ok, aparently its fuse no 10 but don't see any numbering. Edited February 2, 2008 by kyepan Share this post Link to post Share on other sites
pug_ham 245 3 Cars Posted February 2, 2008 The cooling fan has no connections inside the car, its a small self contained loom that only runs between the shunt box, fan, rad switch & resistor. Any fuses for it will be in the shunt box. Graham. Share this post Link to post Share on other sites
kyepan 291 Posted February 3, 2008 Is the thing mounted on the rad the switch or the resistor? its like a small size prit-stick with metal body and plastic connector. perhaps i was not checking the switch at all. Share this post Link to post Share on other sites
ginjaspeed 0 Posted February 3, 2008 yeah thats the switch on the side of the radiator, most common fault on rad fans in my experiance Share this post Link to post Share on other sites
Daxed 7 Posted February 3, 2008 The metal prit-stick is the resistor, the switch is screwed into the rad. Share this post Link to post Share on other sites
kyepan 291 Posted February 3, 2008 cheers for the replies, will investigate further today. Share this post Link to post Share on other sites
Batfink 201 Posted February 3, 2008 Justin. I've ripped out all that wiring from my 205 so you are more than welcome to grab bits of the loom etc as none of it is needed by me. K. Share this post Link to post Share on other sites
kyepan 291 Posted February 3, 2008 cheers may well do mate, so confused about this. an update.. looked at the wiring diagram, its really simple but my test results must be wrong as what's happening makes no sense.. What are the outer pins on the 3 terminal connector to the fan switch in the rad anyone? This evening pa was kind enough to help me by removing the old switch from the old rad , it has three pins, we suspended the buisness end in some hot to boiling water and checking for continuity across the switch. Once it reached boiling point the two outer terminals had continuity, but the central one to either outer ones had no continuity that I could find on the way up to boiling. Then I tried the one on the car, once again when very hot (one past vertical and stop light about to come on) both outer terminals have continuity but not the central one. kept trying different terminals as it cooled. When I took the fan switch connector off and bridged the two outer terminals with some wire, the fan worked on the what seemed to be the lower speed, bridged one inner and each side, nothing. So it seems both switches are knackered on one of the two settings, or i'm testing them wrong, anyone know which setting the two outer terminals is. And also one of the rad circuits is duff, as bridging the 3 pin switch connector with wire should elicit either high or low speed, right? And finally fan switch connector may have poor terminal contact because when the switch has continuity its not making the fan go, even though there is voltage to the female side of the connector. most confused.. once again, any help on which connectors do what on the fan circuit would be most appreciated. I belive the wiring diagram has wires 58a and 58b from the rad fan switch to either the resistor then fan, or just the fan, plus the input from the battery, which is which on the connector? Share this post Link to post Share on other sites
Rob_the_Sparky 10 Posted February 4, 2008 Can't remember details like which pin is which but: You have a positive feed via a fuse to the fan (rad switch?). The rad switch has two outputs on it: The first is slow speed. This drives the fan via the resistor (your prit-stick thingy) The second is full speed. This just supplies power direct to the fan. If I remember correctly the power goes to the fan the switch connects teh ground, eith er direct or via the resistor. To test: Take the rad switch connector off and use a piece of wire to bridge two pis at a time, e.g. 3 combinations, this should: In one position get high speed fan one position give low speed fan last will do nothing If fan runs as above then the switch is dead, rest is OK (a common problem). If slow speed does not work and high speed does then you have a duff resistor (also common) If nothing runs then you have a problem in fan or the wiring to the fan (uncommon) Rob P.S. I have had a car where the connector to the fan switch had an intermittant connection. Wiggle it and all fans start/stop. Worth a try while testing if you think this is a problem. Share this post Link to post Share on other sites
pug_ham 245 3 Cars Posted February 4, 2008 The additional spare brown plug with three pins in should be middle wire 12v & if you bridge with a wire to one side low speed or the other pin high speed. Not really a test of the fan switch though by this method. Graham. Share this post Link to post Share on other sites
kyepan 291 Posted February 9, 2008 hiya, a quick update . its fixed. A new fan switch (the one that screws into the rad) sorted the issue. whilst there i took the opportunity to clean and check the following. fan motor connector block, cleaned, checked pins for corrosion, checked female terminals were not pushed back, bent them in to make proper connection with the spades. switch connector block, cleaned, checked females for corrosion, checked females were not pushed back. fan came on at low speed, not heard high speed yet but its stabilising the water temp. Share this post Link to post Share on other sites
Daxed 7 Posted February 10, 2008 Yeah, my low speed fan keeps things under control in the winter months, even if stuck in solid M25 Friday afternoon bun fights. Mind you, wasn't today stunning, well it was down south anyway, not sure what it was like elsewhere. All praise climate change, shirtsleeve & sunglasses pre valentines day & will end up a shorter drive to the coast in time. Win win. Share this post Link to post Share on other sites
