Cooling fan stays on

[mjk164]

1993 960 24v 214000 mls.
One day this week I found the cooling fan running after I had switched off the engine....well sometimes it does this for about a minute or so; only this time it did'nt switch off and drained the battery. I first suspected the fan relay situated just in front of the battery. I had it off, removed the cover and cleaned up the relay contacts. These are quite easy to get at on this unit but you need a contact burnisher which is nothing much more than a rather dull small file, and finish off with some very fine crocus paper. Put it all back and tested but the fault was still there with the fan still running. Now went to the aircon pressostats which are at the front of the condenser at the bottom, behind the radiator grill. There are three of them here; the outside one is purple and is the high pressure shut off switch, the middle is grey and is the low speed pressure switch and the one closet the center line is brown and is the high speed pressure switch. The grey and brown ones are connected direct to the battery and will operate the fan via the relay independently of the ECM or ignition. By simply removing the connectors in turn I identified the brown high speed switch as being faulty since the fan stopped on removal. Down to the best Volvo agents in London Braydon Motors for a 2nd hand switch and job done. Be careful when you try to remove these switches. There is a Schrader valve between the switch and the aluminium manifold which houses all three switches which alloys you to remove the switch without loosing the a/c gas charge, but you must use two spanners, one to hold the smaller flange nut against the manifold and the other larger one, to unscrew the switch.

[Sabbirz]

Thanks Mjk164,
I’m at the stage where it stays on a few mins after engine is off. Also, when I am coming back from work and am about to turn on the car, the fan starts. Its been very cold here lately and this fan drains the battery just enough to not allow enough power to the starter.. Any idea why it stays on a few mins? I thought perhaps it was doing that to cool down the engine.. but was alarmed when I could hear it doing it before I start it.. and its extremely cold already..

[mjk164]

I think you should check the A/C switches and the bottom of the radiator, accessible from behind the front grill. Follow my previous post and disconnect the brown and purple and grey plugs in turn and if the fan goes off with one of them then you have found the faulty switch. If not then you should suspect the relay (in front of the battery) and try a 2nd hand replacement.

[eddy29]

hi i've been reading ur blog and started to look for the 3 switchs but i can not find them do i need to take the bummper off to find them can you ley me no thanks ed

[mjk164]

Eddy, the blog refers to the 960 (and possibly the 940 as well) and not the V40. These later cars have a different system but will have these switches somewhere, but I am not familiar with the model.
Brgds

[eddy29]

thanks for the reply not to worry i'll work it out!

[Profpriv]

I stumbled across your blog quite by chance and realised that I have exactly the same problem,that the fan continues to run on long after the engine has been turned off.It doesnt drain the battery,yet, but thatll come no doubt.

I thought this was "normal" Volvo 940 behaviour,but obviously not.I also thought that was why the siren alarm is not working,due to voltage drops etc...

The 940 1998 Celebration 2.3LPT also has three switches at the fron of the condensor.Now I know what to do to trace the fault.

Thanks

[Paris6282]

Hi just a thought with 960 engine if thermostat fails in closed position it will produce overheat at top hose/engine not enough sensor then switches fan in partically when engine switched off this has occured twice on both my 960s next time it happens check top hose temp compared to bottem hose also top hose goes solid cure is new thermostat

[DFF53]

I dont know if this helps but I had the same question with my old VW Jetta and apparently they are designed that way to run a few minutes after the car has been switched off. I think its to just to help cool off the engine after ''enthusiastic driving'' because when the car stops there is no airflow into the engine bay. Wasnt it in 90's that Volvo changed to electric fans for 960s and 92 for 940s. Its no big concern , it won't drain your battery.

[CTCNetwork]

Hi,

Not sure that is the case as with both my 840 and V90 all fans shut down when I turn off the ignition...

A search in this forum or the FAQ should turn something up as I have seen this being debated before..
FAQ: Electric Fan Operation....


Des. . .