Astra 2.2 Cooling fan problem

fuzilla

Hey guys!

I've noticed that my Astra 2002 Z22SE engines cooling fan doesn't work.
So far I've replaced the cooling fan, both heater resistors on the fan, the control unit behind bumper for AC and cooling fan and it still won't work.
Also tried taking off the plug from temperature sensor, which I think should start the fan always, but in this case it doesn't.
Also checked the temperature sensors with OP-com and it shows correctly, so I don't think the problem is there.

Actual relays I couldn't find anywhere for the cooling fan, are there any?
Although the control unit and one of the resistors were pre-used parts, so no guarantees there.
Any ideas what to check or replace next?

My car does have AC which also doesn't work. That's actually why I started looking at the cooling fan.

corsaZ22se

Have you tried powering up the fan direct from the battery to see if they work? they will have 1 brown wire (earth) and 2 other wires for each speed (power)
The Astra uses the cooling module instead of relays for the fans. It should still have a fuse or maybe 2 for this though?
You are right in saying with the temp sensor unplugged the fan should come on and put a fault code on too.

fuzilla

corsaZ22se said:
Have you tried powering up the fan direct from the battery to see if they work? they will have 1 brown wire (earth) and 2 other wires for each speed (power)
The Astra uses the cooling module instead of relays for the fans. It should still have a fuse or maybe 2 for this though?
You are right in saying with the temp sensor unplugged the fan should come on and put a fault code on too.

Hey!

Thanks for the reply. I had some time today so I continued this.
Re-checked all the fuses related to the fan, all fine there. Tried feeding direct power from battery to fan, and fan started running as it should.

Also noticed that the plug in my car has 3 pins, as you said. 2 for speeds and 1 ground. While the fans plug only has two, one for power and one for ground. But then I went to check the original cooling fan and it too had only 2 wires going to the fan. So I'm guessing that's not where the problem is.

Next thing I noticed that the groundwire near the fan was really rusted, so I pulled that all the way to battery, just to be sure.
But that neither helped.

Then I again took off the plug from temp sensor and realised that it doesn't give any fault code to the car either, which seemed a little weird to me.
The temp sensor does show correctly when plugged, unplugged it shows -40 degrees. Computer shows that there is another coolant temperature sensor and that gives value around 3,20v but I don't really know if that's a normal value for that sensor.

This still remains an total mystery to me. Could it be that the control unit for fan and AC, I bought as used, was also a faulty one?
Starting to run a bit out of ideas.

corsaZ22se

I have never come across a second coolant temp sensor on a Z22SE?
Just the one on the back of the engine behind the thermostat.
Wounder where your is getting the signal from?
You may have a faulty coolant module, always a gamble with second hand parts.

fuzilla

corsaZ22se said:
I have never come across a second coolant temp sensor on a Z22SE?
Just the one on the back of the engine behind the thermostat.
Wounder where your is getting the signal from?
You may have a faulty coolant module, always a gamble with second hand parts.

Yea it seemed weird to me too, also found just the one sensor from the engine. Just noticed that the computer showed temperature and then some volts for temp sensor, but maybe it's just voltage for the same sensor, don't know.
I think I gotta try another coolant module. The first one I bought used was oddly cheap too, compared to the others I found 😃

fuzilla

Update:
Okay so I ordered another used coolant module, which didn't help either.
Then I measured some wires for module and temp sensor and played with the connections.

Next thing you know the fan starts running when temp sensor is unplugged and now it does give fault codes too.
Ran the car until engine was hot and fan worked as it should. And this was with the original coolant module.
Seems like I fixed it, still dunno how, but I did 😃
Maybe a faulty wire or something, even tho they all looked fine.
The coolant module also did make relay kind of clicks while measuring voltages.

The AC still doesn't work but that's propably just a different problem.
Maybe a leak in the system, but that's another battle for another day.

corsaZ22se

The cooling fans do come on with the temp sensor unplugged, its a fail safe default in case of sensor failure.
Glad you sorted it. Sounds like it was a bad connection somewhere that's good now.
If you have no AC gas none of the AC system will work.

Markswaper

Hello guys 👋

If someone could, please send me wiring diagram of fan controller (plugs swap gone wrong 😐)