you have a faulty engine coolant temp sensor (ect) i had a similar problem with my 2001 s40 1.8. the fans stayed on after switching off the engine, but also mine would rev up to 4000 rpm about 5 mins after start up from cold. replacing the ect fixed both these problems, a genuine Volvo part should cost around £40. the ect is a mojor part controlling the injection system and a faulty one can cause all sorts of problems.
where is the blower motor resister located on an 2004 s40
How do you remove the inside driver's door panel on a 2000 Volvo S40?
it is the switch good luck looking on how to change myself
Where. Is the fuel shutoff switch on a 2000 s40 Volvo
With your fingers
How do u turn on the passenger airbag in a 05 volvo
If your Volvo s40 radio is always off, you can turn it on using the power button. The button is on the left, top-hand side.
.30
Which Tires for volvo S40?
My 2000 Volvo s40 does
Turn the knob on the dashboard near the meters.
Where is the radiator cap on a 2001 Volvo s40?