Heater driver's side mirror?

[Steve McF]

A few weeks back I fitted an new driver's side wing mirror glass, as the one fitted seemed to be a poor quality replacement. The heated aspect of that mirror never worked, although the passenger side one does work. When I took the old mirror off, the wires to the heating element were not connected.

So I was hoping, with the new mirror glass and wires connected, the heated mirror would work. First day when there was some condensation/mist on both mirrors, I tried the demist. PAssenger side cleared, but drivers did not, and didn't seem to have warmed up at all.

Given that one side is working and the other isn't, I would guess it isn't a fuse issue, is it? Or would both operate via different fuses?

And if it isn't a blown fuse, what else might it bee? Poor/dirty wiring connection? Break in the wiring?

[Steve McF]

I found this thread but ultimately it didn't answer the question.

https://www.saabcentral.com/threads/heated-mirrors-not-working.113291/

[sgould]

I think that you will need to get a multi meter and follow the wiring.  Both the voltage  and the earthing.

Each door as two fuses feeding the door module.  The passenger door has fuses 5 & 8, and the driver's door has fuses 5 & 15.   There's no detailed definition of fuse 15, other than driver's door module.  That fuse may well do other things in the door as well. 

There are several connectors and crimps between the power source and the mirror heater.

I think that there's a significant change in the mirror heating control over the years.  Early cars had the heating on as soon as the ignition came on, and stayed on for around 10 minutes.  Later cars would only heat the mirrors when the heated rear screen is on.  Again the heating only stays on for a few minutes.  It can be set to come on automatically with outside temperature.

[aerojon]

Could be an issue with the drivers door switch pack as the mirror wiring comes from that and is controlled via the I bus

early cars heated door mirrors came on with the rear screen..

[Steve McF]

Mine's a 56 plate pre facelift dash model - does that still qualify as an early model? From what I can make out, my passenger side mirror heats up when the rear window demist is on.

[sgould]

I don't know when the system changed.

[sgould]

I had another look at the mirror heating.  And it seems way over-complicated to me.

Phase 1: The mirrors are heated as quickly as possible on start-up.  But it's temperature and time dependent. Heating is on continuously for 6 mins 30 secs if the temperature is below -20ºC.  The time reduces with outside temperature, dropping to zero when the the temp is at or above 20ºC.

Phase 2: This lasts for 2 min 10 secs and the amount of heating is dependent on outside temperature and vehicle speed.  The aim is to keep the glass at +20ºC.  The time is extended by 10 mins if the heated rear screen is operated.

Phase 3: This is the long term heating once Phase 2 is completed.  Heating is reduced to 10% continuously.  If the heated rear window is turned on, the system reverts to Phase 2.  If the heated rear window is turned on when the outside temp is above 20ºC. the mirrors are given full heating power for 20 secs.

Sort that out!!

[phoenix]

Pah. Mine are a bit useless- far less effective than the 9-5. They do work, but very slowly and apparently only when I press the rear window demist.

May have to have a look at some of the readings with Tech2...

[Steve McF]

Pah. Mine are a bit useless- far less effective than the 9-5. They do work, but very slowly and apparently only when I press the rear window demist.

May have to have a look at some of the readings with Tech2...

Did you get a chance to have a look?

I'm fairly sure my mirrors demist when the rear window demist is selected.....my passenger window works, but the driver's does not at the moment.