Hi on my sierra cosworth 3 of the electric windows arent going down the back drivers side one is the only window that is going down anyone have any idea what this may be.

 

MORE than likely to be the switches have got shit in and the contacts are dirty!

 

They do indeed suffer from this but can't imagine 3 being like it ?
Try the back switches on the arm resty bit to see if any different for rear windows ?
If not it's a case of first take the switch out and probe to make sure you are getting output, you know you have a neg and pos there as one works.
The only thing that is common to all three is the switch, so could well be the SW but all three is a bit unusuall.
Itvis most likely to be the switch, can only imagine that previous owners never used these ones ?
tabetha
ps the switch is the same as any four lecky windy sierra so don't pay OTT prices !!

 

try spraying some silicone spry into the conncetions should help

 

Its normally the switch pack gets full of dirt n crap i wud try cleaning it out. I need 2 do mine on my cossie when i get round 2 it.