1995 940 Wagon, 260,000 miles.

I'm pretty sure that previous posts have answered this, but my switch behavior is pretty crazy (flipping on and off, or its own).

Long story short(er), after fixing the busted dizzy cap, the momentary defroster switch started being stuck on. The car was down for another day due to some corroded supplementary wires up at the positive battery terminal.

I cleaned up the cables and clamp and re-soldered a connector to restore normal function. However, the defroster problem has gotten worse.

I took the car on a battery re-charging test drive and the defroster switch started going crazy. It'd come on, and go off, and back on its own - often at a near frenetic pace. Then it would slow down, stay off, then start flipping on and off again. The clicking from the switch is quite annoying.

From other threads it simply sounds like my switch is gone bad and there is no relay.

I wanted to confirm the diagnosis and ask if anyone has the correct part number for the replacement switch. This is the tailgate & side mirror switch.

The only wrinkle is that this is a Canadian (Halifax Plant) car and I've already had to switch out the Canadian headlight switch. I'm not sure if this switch is also some sort of Canadian-spec setup.

Try ebay - there are only a few listings for 900 switches, but 1600 listings for 850 switches.

Such as -

1995 to 1998 Volvo 850 S90 V90 960 Rear Defogger Defroster Heated Mirror Switch

current bid $4 buy it now $5.50 - shipping $3.75

I bought a set of 850 switches which included almost all the dashboard switches for $5

Dear james_a_sousa,

Hope you're well. Volvo VADIS - the now-superseded dealer parts/service database - shows that Part #1362343 (the mirror/rear window heater switch) was not used in 850 or V90 models. This switch was used in 1994 and earlier 960s, and in 940s (up to and including the 1995 models).

It is not obvious - but still possible - that a similar switch from an 850 will fit into a 940. That will depend on the size of the switch, and the connector format.

If the cost is modest, it might be worth a try.

Hope this helps.

Yours faithfully,

Spook

Spook - I only suggested ebay because there were so many listings - I did not look at all of them - the quoted listing was meant to be an example.

The part number could be checked.

Your many posts are quite informative.

I am confused about this whole thread. What defroster switch has to do with the mirrors? I just got a 95, so now think there is something R/Jackal knows about that I don't, on my car.

Dear jerryc,

Hope you're well. I'd guess that all 940s sold in North America have factory-installed rear window de-foggers, i.e., a heating element, that helps to clear condensation or snow/ice. There should be a dashboard switch, that activates the heater.

Most 940s sold in North America also were equipped with mirrors, that have built-in heaters, to help clear condensation or snow/ice. Even if the car doesn't have mirrors with heating elements, I'd guess that the wiring is present in all cars, so that mirrors with heating elements can be retro-fitted.

Thus, if a car sold in southern Florida or California is moved to a northern US state (or to Canada), the non-heated mirrors can be replaced with units that have the heating element. If the factory-installed switch only allows for control of a heated rear window, then the switch has to be replaced with a unit (#1362343), that will control both the rear window heater and the mirror heaters. This is a plug-and-play swap, as the wiring is present.

These switches contains a relay which - as do most relays - eventually fails.

Hope this helps.

Yours faithfully,

Spook

Hmm, so the rear defrost switch in the dash also does the mirrors? (Johnny Carson voice) I did not know that.
The relay is in the switch itself? Interesting. Still learning about 20 year old cars. (One is a 93)

DDear jerryc,

Hope you're well. If your car has a heated rear window (most do), there should be a factory-installed single-function switch (with an icon of a window, with wavy lines). This switch is #1362341 (MSRP = $17). This switch has three contacts. Its case is about 1" (25mm) long, excluding the connector.

To power the mirrors' built-in heating elements (if present), a dual-function switch must be installed. This dual-function switch has a longer case; four contacts; and two icons (one of the window and the other showing a mirror). This dual-function switch is #1362343 (MSRP = $120-125).

So far as I know, the switch swap is all that's needed to control heater-equipped side rearview mirrors. No wiring changes should be needed, as the factory-installed harness suffices.

Hope this helps.

Yours faithfully,

Spook

At least on a 1993 940, the defroster switch/relay has two functions...and two lights. The mirror defrost usually turn off before the rear window demist (left light goes out before the right hand light). Pretty sure a 1995 940 is the same but if yours is a 960...no clue.

Dear Repairmanjackal,

Hope you're well. The switch in question has a relay in it. It is part #1362343. The MSRP is about $120.00.

Volvo VADIS - the now-superseded dealer parts/service database does not show a Canadian variant.

Hope this helps.

Yours faithfully,

Spook

yes, that helps. Thanks

Sheesh.. even Tasca wants $91 for one of these. Looks like a trip to the JY is in order.