Hi,  want to test the radiator fan directly from battery but having difficulty disconnecting the connector

Managed... took me a while to figure it out, radiator fan works fine directly from battery. Thanks anyway.

I was wondering if shorting the coolant temperature sensor terminals to test the rest of the cooling electrical system would be a good idea, If I had a variable resistor from 2k ohms to zero it would be a safer bet than directly shorting out the terminals for sure. But I haven't got one. What do you think?.

The thing is anyone  sure that when switching the AC both fans should spin simultaneously, because in my case only one spins, the smaller one.

Cheers.

 

Does the car have A/c or not?

 

Yes

It is a 2001 Fabia 1.9 SDI with AC

 

Unplugging the radiator fan thermoswitch (F18) connector and bridging terminals of the loom connector is a nice way to test the system. There are three wires to that (quite thin as they are just carrying relay coil currents, not fan currents). Brown to brown/blue should bring on the fan(s) at low speed, brown to brown/green (with ignition switched on) should invoke full speed operation.

Have you checked the relevant fuses?

The below diagram may help you visualise the system:

 

 

Thanks Wino, I will try that, I will check to see on which part of the radiator they are located and will get back to you.

Cheers

Just above where the fan connectors are, about 100mm higher.

 

There are three fuses you should check; strip fuse #5 in the battery fuseholder is the 40A one in that diagram.  Blade fuse #8 is the 30A fuse (under cover next to the strip fuses).

Blade fuse #11 is a 5A fuse going to the radiator fan control unit (J293) that isn't shown in the diagram.

Edited 29 April, 20215 yr by Wino

I have checked all but the 5 amp one in the past, will have a look at that one next, found the thermoswitch, I have large and shaky hands will have a go as soon as I figure out how to access it.

Yes, access is not easy. Be careful not to damage the connector latch when releasing it, also.

 

Does your A/C work?

Because when you switch that on, it should cause the fans to come on after a short time (depending on ambient temperature).  There are two sets of control inputs to the fan control module, the ones from the thermoswitch shown in the diagram above, and another pair of wires from the A/C control module that work the same way. (They go to pins 5 and 6 of the 6-way connector at the fan control module).

Edited 29 April, 20215 yr by Wino

Chequed fuses, are  all OK.

When switching on the AC only one fan spins (the smaller one). Tomorrow I will short the radiator thermoswitch.

It's quite common for the low speed function to fail on these fans; when you tested by directly powering through the fan connector of the big one, did you get it running at both speeds?

I didn't try it come to think of it, could try again, I tested it on the two exterior contacts, there is a central contact, I suppose it will be the central contact plus another one of the two pins. Makes sense what you are saying.

Yep, middle pin to the outer one with brown wire should bring on the low speed, bet it doesn't.

There's a fix you can do rather than replacing the fan, involving an external power resistor, if you fancy saving money compared to fan replacement. At 20 years old though, the fan is maybe due for replacement.

Radiator fan repair, courtesy of Vortex, here and UK-MKIV forum - Handy Topics & Guides - BRISKODA

My latest repair just cable-tied such a resistor to the fan holder:

 

Edited 29 April, 20215 yr by Wino

You are right, I tested it with the multimeter before testing with the battery and between the central pin an the outer two there was complete lack of continuity. So thats why I used the outer pins for the battery test. Is the fan easy to get out?, it looks about cramped.

I think it's not too bad to remove as long as the three screws holding the 'tripod' to the main fan shroud are not too rusted.  Be very careful to get your T30 torx bit fully engaged in the screw heads before trying to turn, or you are likely to round the heads off.

 

The repair looks great and fun to carry out but I do agree that it might be time to get a new fan. I will see  if there are some in eBay or Amazon.

I also checked on a friend's Fabia  and he had exactly the same problem.

Thanks again

Hmm, can't access the radiator thermoswitch, I've disconnected both fan connectors, but can't figure out how to take off the connector's plastic support so I can access the thermoswitch connector. Also I wouldn't know how to unclip it.

Maybe a better approach would be through the top taking the battery support out. But then I would have t connect the battery to test the thermoswitch 

I may be able to find a photo of the connector support taken from the other side. I remember taking one...

Thanks, I have seen you have explained the way to remove the fan switch connector before in a different thread but the image has disappeared from the thread. The clip is on the top so it might be easier if I access it from the top, removing battery and battery support.

Thanks again you're a star

It wasn't the photo I thought I'd taken, but this shows the clip style; not sure how much that helps.

 

If you link me to the post with the broken picture I can probably fix it, which would be good.

I'm not sure you need to do the thermoswitch bypassing test though, I'd be pretty confident that you've got a failed low-speed function on the main fan.

You're assumptions I think are correct, I was just worried that the relay module might be playing up.

It's just that I live in a village at the top of a mountain and now it's beginning to get quite hot (Spain).

It seriously takes me 15 minutes of driving in second gear to get home, and never has the fan made its presence felt. On the other hand there are no indications of overheating. So I might be somewhat overcautious. I will change the fan.

Cheers 

 

10 hours ago, Rocketfella said:

never has the fan made its presence felt. On the other hand there are no indications of overheating.

Yes, but more to the point, does the temperature gauge show the car going onto heat?

I think you are right, I'm being overcautious. There is no indication of overheating. I will replace the faulty fan and stop there, if I see that as the weather gets hotter  that the temperature gauge drifts to the right I will sort it out.