relay changes over, but no live output, no permanent live for wiper park, tested motor and it works fine, fuse OK does the 12v on the live side of the normally open contacts on the relay come from somewhere else, same for the permanent supply is it fed from elsewhere, fuse and relay work fine, problem is with the 12v supply to the normally open contacts on the rear wiper relay and the permanent live supply

ian, September 2013

Only a guess as I've had this problem on a ford.
Everyone tries everything except testing the switch. It may be a fault in the transfer of current to the cable to the motor. A small segment contact on my old Ford broke off so current to switch wasn't being transferred to the wiper on the back window (Cortina estate) worth a shot as you tested everything else.

bob, September 2013