Erratic cooling fan

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dragonflyjewels
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Location: Norfolk

Erratic cooling fan

Post by dragonflyjewels » Sun Feb 10, 2019 10:37 am

Has anyone else had problems with erratic operation of the cooling fan ? Ours started on the GT some years ago when it was parked at my daughter's house and her hubby arrived home from work and heard the fan on, several hours after we arrived. We have had the switch and thermostat changed several times, but it still occasionally turns on when parked and then stays on. Al has now got in the habit of disconnecting it but doesn't always remember to put it back on so he is threatening to fit a switch on the dashboard. It's one of those annoyingly random faults that never happens at the repair shop - we've tried leaving it with them to use as a run around for a few days but it's never done it there.
Last edited by dragonflyjewels on Sun Feb 10, 2019 12:56 pm, edited 1 time in total.
Sylvia

Snazzy - 1993 Paris Blue ES red dipstick 2.0i bought 2001
Lethal Lily - 1991 White Turbo with richmod
hubby has
Sven - 1994 Dark Green GT
Evil Eva 1992 Paris Blue Turbo with Robou mod

Alan 480
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Location: Aberdeen

Re: Erratic cooling fan

Post by Alan 480 » Sun Feb 10, 2019 12:01 pm

Seems 'odd' that it does it with more than one switch . . . ..
I did have odd effects once , but then it failed completely so is now an after-market switch on the top cooling hose (I had it left over from a previous project)
only used the high speed option.

I fed it from an 'ignition switched' cicuit so that it CANNOT run if you get out of the car, saves battery going flat :wink:

I'm never really sure that it would need to run after ignition switched off as the water in top of block etc might stay hot without water circulation and the switch is on the radiator :?
Alan

480 ES 2litre x 2, C30 1.8ES, SS1

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dragonflyjewels
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Location: Norfolk

Re: Erratic cooling fan

Post by dragonflyjewels » Sun Feb 10, 2019 12:59 pm

I fed it from an 'ignition switched' cicuit so that it CANNOT run if you get out of the car, saves battery going flat :wink:

I'm never really sure that it would need to run after ignition switched off as the water in top of block etc might stay hot without water circulation and the switch is on the radiator :?
Thanks Alan, that sounds a better option than a dashboard switch.
Sylvia

Snazzy - 1993 Paris Blue ES red dipstick 2.0i bought 2001
Lethal Lily - 1991 White Turbo with richmod
hubby has
Sven - 1994 Dark Green GT
Evil Eva 1992 Paris Blue Turbo with Robou mod

jifflemon
480 Is my middle name
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Joined: Sat Dec 17, 2016 11:03 am

Re: Erratic cooling fan

Post by jifflemon » Sun Feb 10, 2019 5:02 pm

Does it have a/c? It’s just I thought ac cars have a different cooling circuit so maybe the kids on the ac side of the switching?

If you do decide to do a manual override, put a relay in; rad fans pull a LOT of current!

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dragonflyjewels
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Location: Norfolk

Re: Erratic cooling fan

Post by dragonflyjewels » Sun Feb 10, 2019 6:32 pm

Yes, it does have ac, can I have a translation of kids ?
Sylvia

Snazzy - 1993 Paris Blue ES red dipstick 2.0i bought 2001
Lethal Lily - 1991 White Turbo with richmod
hubby has
Sven - 1994 Dark Green GT
Evil Eva 1992 Paris Blue Turbo with Robou mod

jifflemon
480 Is my middle name
Posts: 927
Joined: Sat Dec 17, 2016 11:03 am

Re: Erratic cooling fan

Post by jifflemon » Sun Feb 10, 2019 7:25 pm

Doh! Kids?? :rofl:

The cooling fan circuit is a simple switched circuit; I’m wondering (as the major components of it have been changed) if it’s the ac side that’s switching the fans on?

WhiteWolf
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Re: Erratic cooling fan

Post by WhiteWolf » Sun Feb 10, 2019 7:35 pm

I know on my turbo in the summer after it has been toed for a bit the cooling fan will stay on after ignition off until the temperature drops to a preset level, it has stayed on for about 15/20 minutes before.. Maybe the sensor that sends the signal for shutoff has had it..
91 480 Turbo white
with Roboumod..
91 480 Es silver

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dragonflyjewels
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Location: Norfolk

Re: Erratic cooling fan

Post by dragonflyjewels » Mon Feb 11, 2019 1:03 pm

Maybe the sensor that sends the signal for shutoff has had it..
Now that sounds entirely logical, I'll talk to the repairman about it.

Thanks for all advice
Sylvia

Snazzy - 1993 Paris Blue ES red dipstick 2.0i bought 2001
Lethal Lily - 1991 White Turbo with richmod
hubby has
Sven - 1994 Dark Green GT
Evil Eva 1992 Paris Blue Turbo with Robou mod

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