Glad that your heated mirror seems to now be working.

For your future reference and to others, one of the common issues with the 700/900 heated mirrors not working or not fully warming is a poor spade terminal connection on the back of the mirrors due to a bit of corrosion. It is after all exposed to the elements. The thing to try is tipping the mirror frame all the way out and the mirror glass rotated all the way out, prying it out a bit with your fingers to make enough of a gap to see behind with a flashlight and access the wires. Get a curved needle nose plier grip on the wire end. Wiggle it partially off the spade terminal, not completely off, wiggle it around then reseat, repeat a couple of times, to see if the heating element now works again. The heat is rather subtle and it takes time to warm. For a longer lasting solution use spray contact cleaner followed by something like DeoxIT conductive anti-oxidant, anti-moisture paste then re-seat. You could try pulling the terminal right off for a better cleaning, but getting it back on working through that narrow gap is extremely fiddly, trust me.

Be careful not to pry the mirror out too much as you risk breaking the plastic mounting. The mirror has a plastic ring on the back that engages into a plastic gimbal. There are two different styles. If you ever need to remove it for replacement then research which one yours is and how to disengage it without breaking.

As a further note on these mirrors, the back of the glass can separate from the rubber coated heating element. This has happened to me twice, both of my '95 940s, both were the left driver mirror and both happened within 6 months of each other -seemed more than a coincidence. It usually hinges out at the top before falling off completely. The first sign of this is noting a vibrating mirror image as you drive. As soon as you notice it, secure with packing tape so it doesn't separate the rest of the way and fall off. The simplest fix is to reattach the back of the mirror to the rubberized heating element. Carefully separate the glass starting at the bottom until you get a hinge where you can flip it out for gluing. Some minor damage to the rubber is okay, but if it really starts to tear then back off and consider injecting glue rather than coating the surface. Clear, marine grade silicone sealant seems the most appropriate here, but is not a good thermal conductor between the heating element and glass. Don't coat the entire surface. Apply a thin bead, just enough to glue it, and do it in a wide pattern so when pressing it on the sealant oozes out thin. I did a W bead pattern inside a large circle to make a thin sealed air space rather that an open air space. It won't heat up as fast, but it seems to work well. Use a 2x4 block sitting on the glass then wrap the mirror tight with bungees for overnight curing. I then used a couple of carpenters F-clamps to squish the sealant down as thin as I could, stopping well short of breaking the mirror assembly. Both reattachments have now lasted a couple of years and the passenger side mirrors have yet to let go.

I am at the stage of needing to more frequently wiggle the wiring so at some point will pop off the glass for a proper terminal cleaning.

If the mirror glass gets broken, there are one or two online web stores that sell unheated mirror glass, sized to fit, that you glue on the face of the broken glass. There's a regular mirror for the driver side and a convex mirror for the passenger side. Some prefer going with a regular mirror on the passenger side, but for the sake of future drivers used to convex mirrors for safer visibility convex is recommended. There's a special glass glue they provide. It's a slightly cheaper option and a much simpler install than a whole new mirror assembly from a wrecker. I haven't bothered to check what's still available in the Volvo parts chain.

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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now