Hi,

I have a v70 2000 classic. The rear heated window is no longer working. I have checked the 30a fuse and it is fine. Also cannot see any signs of damage to the element itself or to the connectors. I have recently had a new passenger mirror put on and as they are linked to the same switch was wondering if the problem could be coming from there. I am not to clever at electrical work so simple instructions for testing would help.

many thanks

S

 

Check for power at the wires to the back glass with the switch on.

 

tech, is their a fuse for that?

 

Yes but if the light in the switch comes on the fuse is good.

 

Just bought a cheap circuit tester. Tested for power at the connectors before the element. Nothing! Could the heated mirror replacement on the same circuit cause the problem? It was from an 850. Thanks for your input so far.

 

Yes that might be the problem.
If you can maybe disconnet the wire to the mirror and see if the back window starts working.

 

Ok,

Disconnected the mirror. Still no power to the back window and all wires look intact. Is there anything else I can check?

Thanks

 

Did you check all fuses already.

 

Just Changed Fuse No 14. 30A Rear Demist (Heated Mirrors) and No29. Rear Demist (power Mirrors) Bulb Failure sensor,(siren) (Seat Belt Reminder) (Cruise Control). Still No Power. I assume am checking for power correctly - red and yellow wire with probe and clip to earth. This works when I check the mirrors with the door panel removed.

 

Yes that is how you should check it.
I would have to try to dig up a wiring diagram to help you more.

 

I would be grateful. My gut feeling is still something to do with the mirror change. Otherwise could it be the the switch in the dash?

 

Possible you can check the switch as well.
Did you only change the glass or the entire assembly.

 

It was the full mirror assembly

 

Then maybe that is it. The wiring might be different as far as positions of the terminals.
Do you still have the old mirror setup?
If so try to compare both and see first if all the colors are the same. If so then check to make sure all the colors are in the same positions.

 

Yup. Its in my garden shed - the mirror housing got smashed but the mirror itself was OK so held onto the the whole thing . Its dark here in the UK so I will check the wiring in the morning - though as you said it should work whilst disconnected.

 

But did you try again with the mirror unplugged after you replaced the fuse?
Maybe it was wrong and blew the fuse and when you replaced it and tried it again it blew again.

 

Checked the fuses again Both OK. Checked wires on old mirror they are the same. Reconnected old mirror everything works except heated rear window. Checked fuses again reconnected new mirror. Still no power to window so guess the problem is not from there.

 

My hatch didn't lock with all the other doors... I just kinda let it go for a while. A few weeks later the rear defroster stopped working like yours.

I found that the wiring harness that leads into the back door was cracked from years of opening/closing. I simply soldered the wires and "electrical-taped" the hell out of them. Much cheaper than paying for a new harness [8D]

 

Just had a look at the wiring around the hatch and can't see any signs of damage. Did you have to remove anything to get to the harness?

 

Im still trying to dig the diagram up.