I'm fixing up an S80 and I don't have wipers. The washer works. I pulled the wiper arms off and put a test light to the wiper motor plug and none of the wipers are hot when I work the switch. The black wire is a good ground at least.

The fuses appear to be okay but there are a few other electrical issues. The door lock button doesn't work and the trip computer is only intermittently working. The trunk also won't lock from the button.

I'm wondering if there is a module or relay that might be the problem.

There is an S80 in a junkyard nearby that I can get a motor from but I'd like to do a little diagnosis first to see if its something other than the motor itself.

 

I'd start by looking at the wiring diagram (volvowiringdiagrams.com) to see if the wipers go through a stand alone relay or a relay inside the CEM (central electronic module) or if there are connectors common to your issues. Also look to see if the fuses are good inside the car as well as under the hood (newer volvos have multiple fuse boxes ). After that I'd say check voltage coming out of the switch (you may have to open the covers at the steering wheel then probe into the connectors to see if the switch is getting voltage in and out).

 

Thanks for the wiring diagram links . I started working my way through and discovered there is an underhood relay . I looked and saw that hole was empty but the hole next to it that is unused had a relay in it


I pulled the relay and moved it and flicked the switch and the wipers started to move then stopped. I realized when I put the arms back on I swapped them left for right and got the long one on the passenger side and it was jammed.

When I got the car it wouldn't start because the ECU relay was missing and relocated to the glow plug socket. Whoever did that moved the wiper relay too I guess