Well well well... Looks like we have a non-operational thermo fan...

I poured in a bottle of radiator flush this morning and went out for a drive. I drove until I started to see it rise from the 'O' and go up past the 'A' (on NORMAL).

Coincidentally enough, it was when I was back in my street, so I was able to pull up and check.

I left the car running and only the passenger side fan is switching on, it appears.

Now for my next questions...

A) What type of relay do the thermo fans take or does anyone have a photo of it?
B) How do I test the current relay that's in there?

I'm half glad that I've found this issue because hopefully it means that once it's repaired, I'm all sorted!

Little things like that can be a pain to figure out. Have you got a service manual?

FIIIIINALLY!!!! It was the goddamn thermo fan!!

Only one of the fans was switching on, so to test the theory of the fans not working and causing the issue, I wired them quickly up to a switch and took it out for a drive. I then went out to dinner and drove it for a round trip of about 60km. It did NOT BUDGE from between the 'N' and the 'O'.

Soooo... Looks like I'll be buying new fan relays tomorrow.

Thank you SO much for the advice!

PS: No, I don't have a service manual.

The manuals can be worth their weight in gold. I have a Haynes AU one here, if you need any info let me know.

If you buy one, buy an Ellerys one though. Much more comprehensive! The Haynes manuals are pretty average.

Yeah, I spotted the Ellery's one the other day at SuperCheap Auto. I'll go and get one in a couple of weeks hopefully.