Breezy_Pete

Yes. 2) is up to you and your wife.

Control unit is probably healthy, fan may also be. The other obvious possibility is that the coolant is not getting circulated to/through the radiator correctly. This could be happening because of a stuck-closed engine thermostat, or possibly a failed water-pump. If the coolant isn't getting to the radiator thermoswitch, the fan will not get triggered even if everything electrical is OK. To check water pump is working, with cold engine start the car with the coolant expansion tank lid off. Observe where the small hose at the top of the tank enters, and see if a trickle of water is coming from it. Get an assistant to rev the engine a bit, and see if that trickle gets stronger. To check thermostat, feel both radiator hoses near the radiator (carefully, avoiding burning yourself on anything nearby) when the engine is fully warmed up, both should be hot, indicating that coolant is going through. If one remains cool, thermostat may be your problem.

Those are fuses. Ignore and attach jump lead to battery positive post/clamp behind them all. If the leisure battery has a largish capacity I can't see it being damaged. Let us know how you get on, please.

Don't worry about the AC. I guess it has low or no refrigerant, which will mean that the HVAC control unit doesn't try to operate the compressor. This in turn will mean that the fan never gets triggered by rising refrigerant pressure. If it is working, it provides a quick and easy way to test fan function, but it doesn't so don't bother with it. I think your fan probably works OK now, but there might be a subtle fault like one or two of the carbon brushes (there are four in opposing pairs) being stuck in their slots. This can make the fan intermittent in starting up. I may have a spare fan (from a more recent car) that will suit your car, I'll research this later for you. Bit busy with work now though.

Oh, progress, excellent! I will think about next step tomorrow morning. Does the AC have known amount of refrigerant in (recent regas?).

I'm thinking of adding loom repair to my window motor repair service so I would do you a very cheap rate for a repair if you like. PM if interested.

Do you still have the GK loom?

Try swapping the unused one in position 6 (no wire attached) to position 3 if you want to be sure. Might be a 50A instead of 40A rated, but will prove the point. Don't replace non-faulty parts, waste of time and money. Not sure about your coolant level observations. One thing at a time.

Fuses all look fine (strip fuse no.3 is the high speed fan fuse on your car, it's rated at 40 Amps). When do you expect delivery of a replacement fan module? Disconnecting battery negative is not a bad idea when testing wire continuity from point to point.

This is how the wiring looks (except you must ignore "Smaller rad fan" V35 if you don't have it) T3i is the three-way, inline connector pair near the bottom radiator hose and thermoswitch.

The relay clicking means that the signal from the thermoswitch is getting through, energising the relay coil correctly. The lack of full speed action from the fan could be due to the strip fuse being cracked/broken/blown, or the relay inside the fan module having burnt-out contacts, or one of the wires involved (from strip fuse to fan module, or fan module to fan) being broken. Can you post a photo of your battery fuse panel?

You have a picture of a wrong type of module at the top of your pictures, why?

Which two, there are three, no? To test low speed of fan, you need to connect the thermoswitch connector loom contact that the brown wire goes to (pin 1) with the one that the brown/blue wire goes to (pin 2). To test full speed you first need to switch on the ignition, then connect the brown (1) to the brown/green (pin 3). Picture here: Most likely the low speed doesn't work, but test both.

O-rings on the high pressure side of the circuit. A (cheap) UV torch will show you leakage locations if dye has ever been added, but usually you can see (PAG) oil adjacent to any seals that have leaked.

Wouldn't that be undoing sequence, tightening sequence would be middle-outward, kinda opposite that @nige8021? I'd guess that it's really not critcial.

It would indeed be helpful to know what part number - exactly, including the crucial letter suffixes - was and is now fitted. Whether the car is pre- or post-facelift would also be useful info, as well as how many electric windows it has (2 or 4).

They were a factory option apparently. Download one of the wiring diagram documents (CFDs) from here: Search the word 'day' within the doc and you'll see how they are wired up in original form. No interest personally, not a fan of lighting mods.

😆

Electrolytic capacitors can rattle if they dry out.

Shame. Doubt there's any coding involved. If you post it to me I could have a look and maybe fix it for you? PM if interested.

Perhaps if you told us what engine it contains?

Whatever you do don't replace the rearmost, single one with anything other than the correct bolt. There's very little clearance above the captive nut on the subframe before you get to the steering rack. Even a 4mm longer bolt than the correct 61mm one will write off the steering rack by denting the cylinder.

That was a bit of an anxious wait. Bloody good to 'see' you here. 😁

It will be a 6R0 part number with a build after March 2010, I'm pretty sure. This means that the key-turned signal goes straight from lock to BCM. That then tells the window motor to go up/down depending on direction of key turn. So there's still suspicion about the power wiring to the motor module, along with the grey/white wire mentioned upthread a bit, and the thin brown earth.

Certainly looks like it, yes. Do the switches light up when the rest of the dash lighting is on? (A check of the thin brown earth wire, which would also affect the switch functions if broken)