740 Blower Motor Question - weak output.

Discussion in 'Volvo 740' started by Jamie, Mar 7, 2006.

  1. Jamie

    Jamie Guest

    My blower motor doesn't seem to make a horrible noise, but because I am
    new to this car I have nothing to compare it to. My best description is
    to say it "purrs".

    That being said, it does not seem like it is blowing as hard as it
    should. When I turn on the defrost, I feel a decent amount of air come
    through the defrost vents.

    But, the normal vents seem a little weak. I would say that level 4
    (high), seems like a 2-3. I checked the squirrel cage and it looked
    clean. So, I am thinking either a door is not opening or closing all
    the way to channel the air to the vents, or something may be clogged,
    thinking the old (input = output) logic. If enough air isn't coming in,
    enough won't blow out.

    Any thoughts?
    Jamie, Mar 7, 2006
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  2. Jamie

    RiverLink Guest

    Depending on the year of your 740, maybe the heater motor is just wearing
    out. If the bearings are getting worn (or rusty), this can reduce the
    speed, putting more strain on the motor. I had the problem, around this
    time of the year when water found its way to the motor shaft, then froze
    solid overnight, blowing the fuse #16 on my 1985 740 GLE.

    Regardless, here the procedure I wrote back then to check the motor and
    replace it if necessary with an inexpensive Delco motor.


    Good luck, or as we say in this part of Canada - bonne chance.
    RiverLink, Mar 8, 2006
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  3. Jamie

    Jamie Guest

    Thanks, I read that article and it's really great. I think to be sure
    I'll just swap the motor when I feel like being "plastic man" again.
    Tough location.
    Jamie, Mar 8, 2006
  4. Jamie

    RiverLink Guest

    Jamie: You have obviously not had the pleasure of replacing a 200 or 140
    series heater motor - a 5+ hour job. So, the 740 is a walk in the park
    compared to earlier designs, although the PV series is the easiest.

    Good luck
    RiverLink, Mar 8, 2006
  5. Jamie

    Jamie Guest

    Hi RL:
    You are correct, after later reading the cost and labor involved, the
    740 seems MUCH better than the 200 series.

    Jamie, Mar 9, 2006
  6. Jamie

    Zyggy Guest

    Have you checked the resistors which control the fan speed?
    It is a quick check they may need replacing.


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    Zyggy, Mar 12, 2006
  7. Jamie

    Jamie Guest

    No I haven't. Thanks for the idea. I'll check those out and most
    probably see if the local parts shop has the $20 motor in stock. If so,
    I'll just replace it.

    The previous owner said an AC hose had a hole in it. I saw a rub on the
    hose from Drier to Compressor. In the next couple months I need to get
    the AC checked out for summer, so this will be an upgrade in itself.

    This is one hell of a project.

    --Engine overhaul in progress
    --Interior cleaned and dash restored
    --Window tint removed and windows cleaned
    --Tires to be replaced
    --360 degree suspension/bushing replacement
    --Hood, roof, trunk to be painted
    --Radio/speakers to be replaced
    --Engine wiring harness replaced
    --Wheel center hubcaps replaced (faded Volvo log)
    --Fuel relay part replacement ordered
    --Windshield replaced
    --Headliner replaced
    --Missing headlight grill replaced
    .....and more!

    Jamie, Mar 12, 2006
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