Engine Fan
 

Hi, can anyone help me with this one before I get to deep. My Kv6 Connie's fan keeps coming on while driving,a couple of weeks ago on a weekend away it stayed on even after checking in at the hotel getting changed etc came down still going. I managed to disconnect the battery until the morning. Reconnected it and all was fine for about 3 weeks until, coming home from work yesterday when it was on all the time, got home still running, so disconnected the battery again. This morning a soon as I connected the battery it started again and hasn't stopped. I've just swapped the resistor for the gold one and its still running. So my question is, before I start stripping the fan off a parts car, is the fan on the Connie goosed and needs replacing or is there anything else I can try? Thanks.

Sounds like a relay sticking inside the control box, not much fun to get at as the whole front has to come off.

Hopefully Arctic, or Stocktake might have a better idea than my guess.

Regards

thanks vitesse, I'll wait and see if they have any suggestions. I don't want to go to the trouble of stripping the fan from the parts car to find it doesn't cure it.

The fan motor has a permanently-on live feed. Switching is achieved via relays on the earth side. A sticking-on or faulty relay will certainly cause the fan to run without the ignition being on. Your description of events suggest this is the likely cause. Of course, the relay may be activated through a fault in the control side. To 'stick on', the relay has to be activated first. Swapping with a new one should give you a clue.


TC

Thanks TC
are these the relays that are in the fan assembly or the one in the fuse box?
Sorry if thats a basic question but I'm no sparky and fortunately my MGR's haven't had many faults so ever had to search for components.

The relays switching the fan on are in the plastic control box mounted behind the fan guard/frame on the nearside.

Is your fan a 3-speed or a resistor moderated 2-speed? The latter has a silver or gold coloured resistor mounted on the frame behind the fan blades. Look through the blades in the 2 o'clock position.

You'll find everything you need to know somewhere on the forum, once it's clear where the problem is.

TC

Almost certainly a relay problem as described, Other causes can be:
The loss of signal from the temp sender.
An overheat situation causing the fan to run after engine is off.

Not sure, but does relay R5 in the engine compartment fuse box supply the feed for the cooling fan?
Might be worth substituting it with another if it does (may be welded on)
https://www.ebay.co.uk/itm/GENUINE-R...MAAOSwJ4hY-Iqs

No David. That's the heater blower motor relay.
Steve,

You don't need to go as far as stripping a complete fan system from another car on the evidence you've presented so far. All you need to do is to check the slow speed relay. This is the small one in the centre position in the control box. You can either do this with a multimeter or by substituting the same relay from your other car.
Relay problems are rare so be prepared for disappointment.

Simon

A little photo to accompany Dave's comment regarding the relay above.
https://i.imgur.com/NZZoiCKl.jpg1

It still remains you will need to remove the front bumper & slam panel,at the least peel back the fan cowling on the control box side to replace the relay or both ? other than that you would need to remove the fan from the car, if your car is gassed you would be better cutting the cowling round the A/C union joints, that way you do not disturb the gas.

allow a minimum of 2.5 hours to do the job.