308 QV Electric mirror and window issues | FerrariChat
Buy

308 QV Electric mirror and window issues

Discussion in 'Technical Q&A' started by davebuchner, Jan 20, 2009.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. davebuchner

    davebuchner Formula 3

    Jun 1, 2005
    2,487
    London UK
    Full Name:
    Dave Buchner
    #1 davebuchner, Jan 20, 2009
    Both electric mirrors stopped working simultaneously. Have checked it is all wired up, but can't see in the fuse box any mention of a fuse / relay for the mirrors. Is it shared with something else? All the regular fuses look intact. I have tried using an ampmeter to test whether there is power on the mirror side of the door switch (I tested it on the last connector before the mirror assembly) It appears that there is some power as the reading changed as I moved the door switch.

    Why would both mirrors stop simultaneously - unless there is no power.

    Any ideas?

    Also my electric windows will stop working - always both together - and then start again for no apparent reason. Sometimes it will be weeks with no problem. Then they both stop. Drive around a bit and then they will both start working again. The fuse box shows the windows to be operated by a fuse (or is it a relay) - not a regular looking fuse, more like a little metal box - excuse the non-techo-speak. This felt warm to the touch last time I checked, when my windows stopped working the other day.

    Is this fuse / relay box something that can give temporary problems, and then come right again?

    Dave
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,931
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Jan 20, 2009
    The +12V power to run your exterior mirrors comes from Fuse #6 which is labeled in the OM as for "Vehicular hazard warning lights - Interior lights - Radio". Are these other things working or not working?

    The +12V power for the windows does go thru a relay -- Relay G (which is shown on the schematic as just the typical Bosch ...113 relay). When they act up again, just temporarily swap in a diffferent Bosch ...113 relay from another function and see if that does, or does not, restore the window operation.

    Do you have the OM for your year/model/version? Also, can you please confirm your F is a 1985 euro (standard) version 308QV.
     
  3. Paul_308

    Paul_308 Formula 3

    Mar 12, 2004
    2,345
    #3 Paul_308, Jan 20, 2009
    US and Euro door wiring is essentially identical.

    Intermittants are often connector related. There is a connector at both doors which easily answers the symptoms of intermittant mirror and window failure. I would plug/unplug/wiggle each while someone is operating the windows and mirrors. If that turns up nothing I would still Stabilant 22A all terminals. Also, a ground failure/intermittant within the doors would cause this. Door ground is NOT through the wiring harness but through the HINGES.

    Aren't intermittants fun?..they totally kill your confidence but when you press a switch and hear an action, fill you with thankfulness.
     
  4. chris marsh

    chris marsh F1 Veteran
    Silver Subscribed

    Aug 30, 2005
    5,764
    Detroit
    Full Name:
    Chris Marsh
    #4 chris marsh, Jan 20, 2009
    I had this problem IIRC it was ground; under the door skin.
     
  5. davebuchner

    davebuchner Formula 3

    Jun 1, 2005
    2,487
    London UK
    Full Name:
    Dave Buchner
    #5 davebuchner, Jan 21, 2009
    Yes, it is a 1985 Euro model.

    Thanks for that info, I will check on the fuse no 6, as far as I know the hazards are working. I will also replace the relay for good measure. I do have the OM for the car but the wiring schematic looks like a plate of spaghetti to me.

    I think the root of the problem is probably a loose connection somewhere - hopefully I can find it!

    Another thing, if one of the door mirrors has a loose connection, say a bad earth, would the other mirror still work?
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,931
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #6 Steve Magnusson, Jan 21, 2009
    Unfortunately, the OM scan from the Owners Site is of such poor quality that I can't make out what's going on inside the switch, item 141. If you post a better quality pic of the symbol for item 141, I can answer more directly (there are actually two direct grounds -- one for the switch and one at the RH mirror, the LH mirror has a direct +12V connection and receives ground signals only via the switch). However, since you have lost operation of both mirrors, (and if the other things on fuse #6 are working) I would start with checking that +12V power and ground is reaching the switch:

    Measure the voltage on pin 2 (the brown/red, MR, wire = +12V) relative to pin 4 (the brown, M, wire = ground)

    If this is +12V -- not a good sign for the switch

    If this is not +12V, measure the voltage from pin 2 (the MR wire) to a different known ground

    If this is +12V, the connection of the brown (M) wire to ground is bad

    If this is not +12V, you have a bad connection between fuse #6 and the switch
     

Share This Page