I usually find this problem with the switch on the door. Not the joystick the one that switches from left to right. It get pretty dirty. If one mirror is working, I would suspect that the switdh needs cleaning.
According to my book the FUSE is located in the Auxiliary Fuse box above the Main fuze box. It is Fuse number 5 30A. There is a RED/BLACK HOT wire that goes directly to the Joystick Switch. It should always read 12v. This fuse also controls the Lamps throughout the car. If those work, then I would suspect the RED/BLACK wire going to the switch is severed from opening and closing the door for many years. There are NO relays. If the fuse is good, check to see if there is 12v at the fuse, if there is 12v, remove the switch and check for the 12v at the Joystick switch. If the 12v is not present at the switch I would check the wire to see if it's severed. Hope this helps!!
That's a great help, thank you again alfasrule
I had a look on cardisk but couldn't see any mention of the mirrors or the power to them?!
Thanks for giving me the info though - I'll check all that out and see what happens
edit :all the lamps work inside the car so you are probably right about the wire being broken)
I know shop manual says F5 fuse in G2 aux fuse box is 30A in mirror wiring diagram but that is an error. It should be 10A. It is correct over on lamps- ground illumination, door opening, trunk lighting diagram.
If those are working then fuse should be OK and mirror switch probably to problem as it is usually the problem when mirrors don't work.
When my mirrors decide to stop working, I flip the L and R switch back and forth maybe a few million times (an exaggeration) and then they both start working again... usually. I try to use the switch every so often so that they keep working. Mind you, this is all after I removed the switch, took it apart and cleaned it with contact cleaner (and re-greased it) a few years back.
My experience exactly matches what Charles reports (the L-R switch being the main weakness), though I do in addition have a motor on the left mirror that only responds when I push on the glass and then works for a month before it stops again (like 'seat motor syndrome'). I still think on the whole the switch is the problem in 90% of the cases (so much so, a second-hand switch probably won't work until it is dismantled and cleaned), but it would be worth checking for 12V there just to be sure.