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Cooling fan

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Hi - Been reading a while but this is the first post. Now the proud owner (for the last month or so) of an '87 944 Auto. Very lovely, I'm already well into advanced plans for an S2, but in the meantime I have a bit of a technical issue that is presently slowing my progress.

On arrival home last night the engine cooling fan continued after the keys were removed from the ignition. I didn't think this was an issue as the car had been driven a considerable distance.

This morning however the fan was weakly turning (engine cold) and the battery was pretty much flat. I guess something isn't disengaging. Can anyone give me some pointers?

Cheers
Ian
 
Obviously , the fan is supposed to go after shutdown for a while, but not so long as to kill the battery! The most common failure is in the fan relay, replace that and you should be OK. If it still persists, then you may have a dodgy temperature sender in the radiator.
 
I think the radiator switch might be more common - that was the fault for mine. You should hope it is as it costs about £20 and some skinned knuckles and coolant whereas the relay is £120 or £150 or something.[FONT=verdana,geneva"] [FONT=verdana,geneva"]Pulling the fuses works in the interim. Number 15 and one other I didn't have to bother about as my second fan didn't work [8D][FONT=verdana,geneva"]
 
ORIGINAL: Fen

............. Number 15 and one other I didn't have to bother about as my second fan didn't work [8D][FONT=verdana,geneva"]
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Number 10 & Number 15. Beaky had a fan running session in Scotland - just the once it would seem. I made up a temporary switch loom which plugged into fuse hole 10 and 15 and came out of the underside of the fuse box to a couple of switches in the passenger foot well. You can use insulated male spade connectors to plug in where the fuse feet go and connect the fuses within the line using insulated female spade connectors. All quite clever, though I say so myself.

I now have a replacement rad switch to fit (thanks to Tony who collected it from Glasgow OPC) but have decided that it would be remiss of me not to replace the header tank with a nice new one when I drain the coolant to swap the switch.
 
You're not jealous of Rick and I with our lovely white header tanks are you? I assume in Rick's case like mine it's been replaced as a performance mod though, not just for the tartiness [;)]
 
ORIGINAL: Fen

You're not jealous of Rick and I with our lovely white header tanks are you? I assume in Rick's case like mine it's been replaced as a performance mod though, not just for the tartiness [;)]
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You can add Tony to that lis as well [:)].

Tartiness! Heavens no! It is a critical check to ensure your header tank is at the right level - not easy in mine as it is all cream coloured and opache. Oh, and I spotted some cracks forming in the top - well at least that's what I'm telling Belinda [:-]
 
My 1989 S2 does not run it's fan(s) when the ignition is off. If I have been for a decent drive the the fans will run for 10 minutes after the engine is stopped, but only when the ignition is on.
 
Thanks Justin - that's exactly what mine does. What I can't understand is that if I jumper pins 2-3 the fans run even with the ignition off.

Any other S2 owners able to comment? [;)]
 
ORIGINAL: hotblack944

Fan should run even with ignition off if the coolant is hot enough.

Jim.
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Hmm, that's what I thought. I don't understand whats happening with the thermo-switch though. Linking it manually makes the whole thing work as expected. The only other possibility is if pins 1, 2 and 3 ALL link together when the switch trips instead of in stages. That's one thing I will try replicating tomorrow.

One thing I can tell though - the switch is only £7 but it looks a right bugger to fit. Have to drain half the coolant and shave an inch off my forearms.
 
Sensor must be knackered then. I know the relay is OK 'cos I've tested it independantly and the system runs as specified if I bridge the sensor manually.
 
The fans on mine run on if it is hot - usually for 90 seconds or so, but I think they have run for longer on a couple of occasions.

Sorry - I can't talk about fan behaviour other than this - I don't know whether they are running fast or slow (or what the pins are doing.)


Oli.
 
Picked up a new thermoswitch yesterday from GSF (£8) so I'll let you know what difference it makes.
 
ORIGINAL: xenon

Picked up a new thermoswitch yesterday from GSF (£8) so I'll let you know what difference it makes.
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Hey, big spender!

OK, hope it solves the problem for you. Did you test the behaviour of the old switch in any more detail?


Oli.
 
[:D]

No. I figured it must be an iffy switch because a) the relay is new, b) I tested the relay and c) the fans work exactly as they're supposed to if I manually bridge the contacts.

My only reservation is the fact that the switch has been in there since the dawn of time and I'll probably strip the threads getting it out and wish I'd never bothered.
 
Good logic.

Threads? Shouldn't strip them, just go easy with the spanner when you undo it.

I find that a can of penetrating spray is one of the most useful things in my toolbox whenever I do work on an old car. Changing my suspension recently used quite a quantity, but I did get everything out, without damage, first time. (Of course I did it all up with copaslip so it will come apart much more easily next time, but I don't think I'll be doing that job again on the S2. Given that the last suspension set managed 18 years, it'll be on the scrap heap before it next needs doing!)


Oli.
 
Yeah, WD40 is worth its weight. Some of the threaded inserts on the radiator are plastic and some are brass, that's the worry.
 
Normally when the switch fails it leaves the fan running all the time, but I guess it can fail in a different way also. Let us know..
 
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