snattrass 0 Posted September 12, 2008 Just after taking short drives round town at about 16C temp first thing in the morning and when I get home the aux fan comes on seemingly at the drop of a hat. I checked the water temp and it was between 80 to 85C. Is this correct - just wondering whether I am seeing the first signs of something more serious or nothing to worry about? Kind regards, Simon PS Yes VR6 model Quote Share this post Link to post Share on other sites
DanVW 0 Posted September 12, 2008 Check the wiring around the fan temp switch (bottom r/h corner of the rad as you look from the front) for shorts etc failing that pull the switch out and replace it :-) weird it comes on early though, normaly the fail and dont come on at all or not till the 2nd stage kicks in. Quote Share this post Link to post Share on other sites
snattrass 0 Posted September 12, 2008 If it was indicating water pump (or the dreaded Head Gasget) then I assume the water temperature would be getting pretty hot pretty quick esp round town etc? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted September 12, 2008 What engine? VR6? 80 deg C is too low, obviously! If it's not a defective temp gauge, it could be the yellow temp sender in the thermostat housing. It's the reference sensor for both the dash gauge and the also for the fan controller box (the big box bolted to the nearside turret). If the fan / after run controller gets a short or bad signal from the sender (brown wire with red tracer), it will activate the fans way too soon. Quote Share this post Link to post Share on other sites
DanVW 0 Posted September 12, 2008 As a further thought, could it be an after market low temp (80deg) fan switch? Fitted by the PO? Quote Share this post Link to post Share on other sites
snattrass 0 Posted September 12, 2008 Hmm interesting thoughts. I've broken 2 thermometers but from taking readings of the water temperature in the radiator expansion tank when the fan cuts in it looks like the 80-85c reading on the car's water temperature display is about correct. Doesn't seem to be any loose wires or anything around the yellow temp sender in the thermostat housing that I can spot. Will check again later. If there were shorts surely the fan would switch on and off at random rather than come on consistently at this lower 80ish degrees? I know it has had a head gasget replaced by a PO at some point in it's life but not sure whether it had an after market low temp (80deg) fan switch fitted. Didn't even know such a thing existed. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted September 12, 2008 Sorry, I was kind of hinting at replacing the yellow sender! I wasn't very clear on that! The sensor has 2 different outputs. A variable one for the dash gauge and a fixed output for the fan controller. It could be that the fan output has gone and triggering the fans too early. It's what happened on mine, so thought I'd share the wisdom, LOL! Quote Share this post Link to post Share on other sites
snattrass 0 Posted September 12, 2008 Thanks cheesewire i'll bear that in mind. Is it actually a problem if the fan is kicking in too early as long as it doesn't come on when i'm driving along - it usually just seems to come on when i stop. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted September 15, 2008 Not really, it'll just flatten the battery if they stay on for ages! Quote Share this post Link to post Share on other sites
