Righto so after the temperature gauge went all the way up today and the light went on, I decided to get around to fixing that fan. Turns out it was the first relay, switched that over and robert's your father's brother, temperature went straight down with both fans working. I think the problem was that because it was the passenger side fan that was busted, and thats the side where the hot coolant goes into the radiator, it wasn't being cooled properly. So if I had to have a broken fan it would've been better to be the right one... But all fixed now.

On a side note to the boiling coolant though, I am thinking it may be just the heat soak thing, but might get around to replacing the radiator cap because I'm not sure if its ever been replaced. Also it turns out that the mechanic just topped the coolant up, but didn't flush it. He didn't pull a dodgy, just a communication error. So I'll be probably doing that this weekend as again, I'm not sure of the last time it was done, and then I'll see if it improves.

Hey mate did you end up fixing this issue, I’ve got the passenger thermo fan code too. My AC also isn’t turning on so I think it may be thermo related as I’ve tested every possible part of the ac circuit.

Start a new thread if you have questions.