940 Thermo fan not starting

Massey165

Can anyone suggest where I start looking?

Essbos

Proper coolant/water mix is essential.
The ground wire for the electric fan relay can corrode or become loose, so check that.
Maybe also worth 'hot wiring' the fan to ensure that hasn't burnt out.

Major Ledfoot

Massey165 wroteCan anyone suggest where I start looking?

What have you checked so far? (just so we're not repeating anything you've done)

http://volvowiringdiagrams.com is your friend.

And https://www.brickboard.com/FAQ/700-900/FAQSummary1.htm is one of your close mates, or should be.

Philia_Bear

It does not kick on until 107c for low and 114c for high speed
It can take a considerable amount of time to be warm enough to turn on

Easiest way to test is via ac
If not turning on for ac it means there is no gas in the system

Massey165

Thanks to everyone for the suggestions and technical stuff, a/c not working so will start there