Mk2 1.6 petrol overheating issue

[Pullingmyhairout]

Evening,

I own a Focus Mk2 2007 1.6 petrol (non Ti-Vct) estate with about 145k miles.

Driving home from work today, I hit very slow stop-start traffic and turned the AC on.

Within a minute or two I noticed the temperature gauge on the dash was beyond the half way and climbing rapidly. Within a few minutes the needle was in the red with the dash message showing engine overheat.

I quickly pulled over, shut the engine off and had a look underneath. I should note a couple of things:

1) Coolant level was only slightly below minimum. This has been like this for a while however and I top it up a tiny amount but the level returns to the same point and no lower within a few weeks.

2) The radiator fan isn't kicking on at all. Not even with the AC on.

3) There is an audible on-off hissing noise from behind the dash and I can hear the AC compressor cycling on and off. The engine also seems to stutter slightly when the AC clutch engages. This is noticeable on the dash as the idle RPM hunts up and down between 750 and 1100 rpm.

4) No leaks under the car. A tiny amount of coolant residue under the expansion cap and also around the two return hoses into the tank. Could this explain my subtle coolant changes? 

I removed the expansion cap tonight and ran the engine for 15-20 minutes with the heaing on full to see if there were any airlocks but nothing happened. No overheating while doing this but still no fan. 

Could my AC and fan/overheating issues be linked? Any pointers would be helpful before I start pulling things apart.

Thanks 

[unofix]

Do you have a multimeter and know how to use it ?

Is there voltage at the Fan motor terminals when it should be running ?

[Pullingmyhairout]

5 minutes ago, unofix said:

Do you have a multimeter and how to use it ?

Is there voltage at the Fan motor terminals when it should be running ?

I'll dig it out tomorrow and report back.

Thanks 

[Pullingmyhairout]

Had the AA out today they've tested the fan with a direct 12v feed and it works. 

AA guy reckons it's the control module on the back of the fan as the blue control wire from the ECU/PCM is OK. 

Seems like a reasonably easy fix but does anyone know what the part number is? Found some on eBay that look similar but apparently they're not compatible. 🤔

Thanks all for your help. 

[Pullingmyhairout]

Update:

I've replaced the control unit on the fan and the fan now works. Time will tell if this solves the issue.

However I now don't have aircon. I can't hear the compressor engage and I've a sneaky feeling it's either knackered or the overheating issue has caused all the gas to leak out so it's not turning on. 🤔

[unofix]

2 hours ago, Pullingmyhairout said:

However I now don't have aircon. I can't hear the compressor engage and I've a sneaky feeling it's either knackered or the overheating issue has caused all the gas to leak out so it's not turning on

As @StephenFord will tell you, "take the car to Kwik Fit and get it regassed. If it doesn't work they give you a refund"

Try this it might help while you fix the next problem 🤣

[Pullingmyhairout]

Do you get a complimentary bottle of the stuff if a Kwikfit regas doesn't work? 🤣

46 minutes ago, unofix said:

As @StephenFord will tell you, "take the car to Kwik Fit and get it regassed. If it doesn't work they give you a refund"

Try this it might help while you fix the next problem 🤣