Fan Control Unit

[LittleSole]

;) Hi,

12 months on and the ac on my 1997 Galaxy glx 2.0 petrol is still not working properly ... intermittent, but off more than it's on.

Hoping for a hotter summer so I've decided to try again and fix it.

 

No problems with gas system (compressor, gas, etc) are all absolutely good.

It's an electrical/control fault. I've changed the pressure switch and checked all relays, fuses and connections.

 

I'm considering changing the Fan Control Unit (the fans run fast even when the engine is cold). However it's not cheap (

[seatkid]

;) Hi,

12 months on and the ac on my 1997 Galaxy glx 2.0 petrol is still not working properly ... intermittent, but off more than it's on.

Hoping for a hotter summer so I've decided to try again and fix it.

 

No problems with gas system (compressor, gas, etc) are all absolutely good.

It's an electrical/control fault. I've changed the pressure switch and checked all relays, fuses and connections.

 

I'm considering changing the Fan Control Unit (the fans run fast even when the engine is cold). However it's not cheap (

[LittleSole]

Thanks SeatKid,

 

One concern is that the engine cooling fans run even when the a/c unit is turned off ... they start immediately the engine is started (even when cold) ... and they're fast!. Which is why I wondered about the Fan Control Unit.

 

I noticed there

[seatkid]

Thanks SeatKid,

 

One concern is that the engine cooling fans run even when the a/c unit is turned off ... they start immediately the engine is started (even when cold) ... and they're fast!. Which is why I wondered about the Fan Control Unit.

 

I noticed there

[LittleSole]

Sounds good, SeatKid. Thanks.

 

;) Interestingly ... the engine has been running cold = the temp' dial on the display never shows warm and the heater never blows warm (unless in a queue of traffic) ... but until recently I hadn't realised there could be a link with the faulty ac and the 'cool' engine = I had thought they were seperate ... seems maybe not.

[seatkid]

Sounds good, SeatKid. Thanks.

 

;) Interestingly ... the engine has been running cold = the temp' dial on the display never shows warm and the heater never blows warm (unless in a queue of traffic) ... but until recently I hadn't realised there could be a link with the faulty ac and the 'cool' engine = I had thought they were seperate ... seems maybe not.

 

There is no link between cool engine and a/c - the fan issue is a red herring - you must have a water thermostat issue to add to your list.

[LittleSole]

Sorry ... I think I misled you ... I didn't think there was a link between a cool engine and a/c and I know, at some stage, I must check out/replace the water thermostat!

 

I had been told that the Fan Control Unit is involved in the management of the a/c (sometimes {some engines} just for the fans ... and {in other engines} sometimes for a/c management too ... +/- together with certain relays) ... and it seems so from technical information and wiring diagrams I've now found ... but it seems each engine type varies in what-controls-what.

Which was why I wondered if the Fan Control Unit might be, in some way, the cause of my a/c fault.

But I'm not fully convinced and, as you say - the fan issue could be a red herring.

 

I'd take it to an auto-electrician ... but it seems it'll be very time consuming to track down the fault = too expensive for me ... especially considering the age of the Galaxy. So I'm just plodding my way through it all.

 

Your advice is much appreciated.

[big blue]

Hi, not shure if this helps or not - but i think the 'pink' sensor under the fan relay bracket measures the temperature on the high pressure a/c pipe (this pipe should get hot) - looking in the Haynes manual it looks like it should be open circuit (untill it gets hot then closed circuit - i think).

The only problem is mine gives me a reading of 13 to 16 ohms when measured (engine flat cold a/c pipe flat cold) - this to me would appear to be closed circuit - not open like the Haynes manual would indicate.

 

Hope this helps

 

 

Big Blue.

[Linhurst]

Sounds good, SeatKid. Thanks.

 

:25: Interestingly ... the engine has been running cold = the temp' dial on the display never shows warm and the heater never blows warm (unless in a queue of traffic) ... but until recently I hadn't realised there could be a link with the faulty ac and the 'cool' engine = I had thought they were seperate ... seems maybe not.

 

Hi LittleSole, did you ever resolve your problems?

 

Here are mine with a 1996 FORD GALAXY 2.0 GLX:

 

The engine has been running cold = the temp gauge on the display never shows warm & only moves of cold at motorway speed. Garage replaced the "faulty" temp sender to the gauge but made no difference. Asked different garage to check/replace thermostat however they reported the radiator cooling fan running at all times was the cause so suggested an auto-electrician. I was using ECON mode with climate control so air con should be off. Auto-electrician report no fault codes on ECU or faulty sensors so much expense and no idea how to resolve. Recently red warning light also flashes above temp gauge.

[dave030445]

the red flashing warning light means low on water, this would also not give you a good heater. Edited March 16, 2010 by dave030445

[Linhurst]

the red flashing warning light means low on water, this would also not give you a good heater.

 

Thanks for the suggestion Dave. I have checked the coolant level and it is at MAX. level. I do get warm air though not really hot. I understand the red light can also mean a cooling fan fault? Would this mean that I now have a fault code to help diagnosis?

 

As an update a local garage was doing a deal on air-con top up. I have just returned from the garage who reported they could not recharge due to a leak in the air-conditioning. They do not do repairs. Could this be related as it was one suggestion the auto-electrician made? They did not think so and suggested an auto-electrician as a relay may be the problem with the fan.

 

So fan relay, fan control unit, other temperature sensor, other sensor or something else? I just don't know and nor do the local garages that I have tried.My initial instinct was the thermostat as if water was not circulating (thermostat closed) then engine should warm up regardless of the fan being on? Three different garages have told me it is the fan that is the problem not the thermostat but don't know why the fan is on.

[chrispb123456]

Here are mine with a 1996 FORD GALAXY 2.0 GLX:

 

The engine has been running cold = the temp gauge on the display never shows warm & only moves of cold at motorway speed. Garage replaced the "faulty" temp sender to the gauge but made no difference. Asked different garage to check/replace thermostat however they reported the radiator cooling fan running at all times was the cause so suggested an auto-electrician. I was using ECON mode with climate control so air con should be off. Auto-electrician report no fault codes on ECU or faulty sensors so much expense and no idea how to resolve. Recently red warning light also flashes above temp gauge.

Hi have your garage actually replaced thermostat or not. Try this, with engine cold start engine after 10 mins ticking over feel the large hose going to the top of the radiator if the hose feels warm its very likely the thermostat is open or partly open which means the coolant is circulating through the radiator while the engine is still cool, the cooling fans will run even when engine is cold if the air con is on AUTO. ECON as you say does turn air-con off, check air-con pump with engine running look at the pump if the centre part of the pump drive is turning with the pulley air-con is on, if the centre shaft is stationary it is off.

Red flashing light is low coolant level/and/or overheating.

Does car loose water are you constantly topping up if you are you may have head gasket going/gone.

Also check engine oil dipstick is the oil dark, you dont want any white milky looking mess in the oil, called mayo in the trade.

See how you get on with that.

Chris ;)

[Linhurst]

Thanks Chris,

 

I have been to three different garages to get the thermostat replaced however when each discovered the fan was on they said the thermostat was not the problem. I am still not convinced but then I am no expert and electronic control has made diagnosis much more complex. I will check the hose for warmth when it stops raining:-)

 

Coolant level is at max and I have never needed to top up. There is no water in the oil. Air locks unlikely as the system has not been disturbed and the red flashing warning light only came on after the battery & clutch was replaced recently.

 

Temp gauge shows cold and red flashing light is on as soon as you start the car so engine is not overheating. My problem is over-cooling. Normally this would suggest faulty thermostat or gauge sender unit. The gauge sender unit was the original diagnosis and was replaced with no change.

 

The temp gauge does move from cold when at sustained high speed but not reach half way which is the normal steady state. I understand from LittleSole that he has resolved his problem with the fan but not with the over-cooling so these problems may be unrelated?

[dave030445]

hi if the red light flashes as soon as you start the car, and there is water in the bottle then the senser is faulty in the bottle. Mine had scaled up. i had to remove bottle and clean out i used limescale remover

[Linhurst]

Dave, thanks for the suggestion. I found one of the wires to the sensor on the coolant bottle behind the battery was broken off.

 

1. A garage recently replaced the battery and the light was flashing afterwards. They said the removal of power to the ECU had reset the fault code and the problem was related to the fan. Looks to me like they disturbed the wire while replacing the battery. Not sure how to fix this as the connector does not look like you can take it apart but at least there is no serious problem. Looks like this is nothing to do with the main problem.

 

2. Fan was not running today so after a short run I checked the top hose and it was warm (not hot). The temperature gauge was still in the white cold area so looks like the thermostat is not closing properly allowing water to circulate to the radiator before the engine has reached temperature. I guess there may be a separate problem with the fan that is just aggravating the problem with the thermostat?

 

Looks like next step is to replace the thermostat and see if this helps.

 

3. Is it possible to stop the fan working with the air conditioning while retaining fan function to cool radiator when hot? The air con has a leak it is not working anyway. I understand that there is a low speed and high speed circuit. Are they used for different functions? The fuse/relay locations do not appear to match the Haynes manual. Look like there may be three separate problems.

[dave030445]

No dont think you can get into those plugs, you will either need to get a plug from the breakers. (with some wire on it) and join them up. Or do what i did was cut the plug off and crimp 2 small spades crimps, on they are just the right size to go on the bottle.

[Linhurst]

Thanks Dave, I cut off the plug and used two small spades as you suggested. The light no longer flashes so that was one problem solved.

 

I have replaced the Thermostat and the engine now gets up to temperature so that is my main problem solved. The seal on the old thermostat fell apart and although closed the old thermostat could be opened with light finger pressure.

 

The cooling fan still appears to have a mind of its own and comes on when the engine is not hot. Given the time, effort and expense so far without fixing this I am minded to give up and live with it.