Volvo 2003 XC90 electrical issues
 

Hi All. I have a 2003 xc90.
Today I put the key into the ignition all the lights came on but it failed to turn over, lights dimmed but no go. Can I ask if anybody has any thoughts. cheers.

Battery? Have you tested it?

On the same theme, loose terminal connectors, any work been done on the car recently?

Have a similar problem with mine at the moment and diagnosed it today as a stuck ac pulley. The pulley is so stuck that it shredded a rib off of the aux belt and stops the crank turning.
I would also still check the obvious such as starter motor, earths and battery. I also know that Volvos can be strange with key battery’s, sometimes when the key battery is low the immobiliser doesn’t like it.

Really interesting post, I had not thought it would prevent the crank turning! That’s a really sieved AC!

Good luck with the repair.

My initial thought to op is battery or earth issues?

When I tried to crank the car all pulleys would turn except the ac one. The Tension was so tight that all the pulleys would only manage to turn about 1 quarter rotation. Took me a while to diagnose as it was a strange problem. At one point I really thought my engine had seized Or time went seriously wrong. But turned out to be a fairly cheap easy ish fix.

Impossible. the key battery has nothing whatsoever to do with the immobilizer.

The immobilizer transponder is fully passive, it does not run on the key battery. It is powered by the ring antenna around the ignition lock.

The key battery powers only the remote central locking and unlocking.

Have experienced the same on two cars over the years - first on a S60 and secondly on a Toyota Celica. in both cases the AC compressor had seized. Easy fix but you need the system degassed before disconnecting the pipes.

I would have thought the same for any other car but for some reason there are quite a few cases of Volvos not starting just because of a dead key. Seems more common on xc90 though.

A dead key due to a dead transponder can cause a no start condition.
But a dead key due to a dead key battery can still start the car.