Results 1 to 7 of 7
Discuss 4Runner blower problems in the alt.autos.toyota forum at Car Dealer Forums; Hi folks, I'm trying to troubleshoot a non-working fan on a '91 4-Runner and was ...
  1. #1
    Alex
    Guest

    Default 4Runner blower problems

    Hi folks,

    I'm trying to troubleshoot a non-working fan on a '91 4-Runner and was
    wondering if someone can offer some tips. (The fan in question is the
    inside blower fan/AC.) It no longer comes on. This happens at ALL
    speeds, includiing the highest. I've checked whatever fuses I could
    think of and even have given the 'CDS FAN' relays a few wacks with a
    screwdriver, just in case they got stuck... No luck.

    I've taken off the glove compartment and gotten to the motor, but am
    not really sure what to look for there. I've disconnected what appears
    to be the power supply wire to the motor and, with the fan switch
    turned all the way up, hooked up a voltmeter to all the terminals,
    every which way I could think of. I can't seem to register a voltage
    there. (BTW, should I still expect to read somewhere around 12V DC
    there, just like I do at the battery?) This seems to imply that
    there's no power to the motor, which would then rule out the motor
    itself. However, I'm:

    1. Not 100% convinced that I'm measuring voltage in the right place and
    in the right manner
    2. Even if I am, am not sure where to go look for the problem at this
    point.

    I've also done my best at trying to measure voltage across the relay
    terminals (again, CDS FAN #1 & 2, with the engine running and fan
    switch all the way to ON). And again, I've been unable to register any
    kind of voltage, but am not sure that I'm doing it correctly.
    (Measuring across the 'already ON' terminals, not the switched ones.)

    Can someone offer some ideas to try next? Could it be the switch
    itself? Is there an easy way to test that theory? Should I just get
    the right relays and try those? (Are the CDS FAN the right relays?
    Where can I get them?) I've also read some references in this group to
    a blower resistor pack on the motor, but it sounds like since the motor
    won't come on even at highest speed, when the current should flow
    directly to it, this may not be the culprit.

    Please help before I do any more damage. I know just enough to cause a
    blackout in the neighborhood. :-)

    Thanks in advance,

    Alex




    › See More: 4Runner blower problems

  2. #2
    Ray O
    Guest

    Default Re: 4Runner blower problems


    "Alex" <gsargucci@netscape.net> wrote in message
    news:1166546817.433446.237110@i12g2000cwa.googlegr oups.com...
    > Hi folks,
    >
    > I'm trying to troubleshoot a non-working fan on a '91 4-Runner and was
    > wondering if someone can offer some tips. (The fan in question is the
    > inside blower fan/AC.) It no longer comes on. This happens at ALL
    > speeds, includiing the highest. I've checked whatever fuses I could
    > think of and even have given the 'CDS FAN' relays a few wacks with a
    > screwdriver, just in case they got stuck... No luck.
    >


    I believe that the "CDS Fan" relay is for the condenser fan in the engine
    compartment and not for the AC/heater fan.

    > I've taken off the glove compartment and gotten to the motor, but am
    > not really sure what to look for there. I've disconnected what appears
    > to be the power supply wire to the motor and, with the fan switch
    > turned all the way up, hooked up a voltmeter to all the terminals,
    > every which way I could think of. I can't seem to register a voltage
    > there. (BTW, should I still expect to read somewhere around 12V DC
    > there, just like I do at the battery?) This seems to imply that
    > there's no power to the motor, which would then rule out the motor
    > itself. However, I'm:
    >
    > 1. Not 100% convinced that I'm measuring voltage in the right place and
    > in the right manner
    > 2. Even if I am, am not sure where to go look for the problem at this
    > point.
    >
    > I've also done my best at trying to measure voltage across the relay
    > terminals (again, CDS FAN #1 & 2, with the engine running and fan
    > switch all the way to ON). And again, I've been unable to register any
    > kind of voltage, but am not sure that I'm doing it correctly.
    > (Measuring across the 'already ON' terminals, not the switched ones.)
    >
    > Can someone offer some ideas to try next? Could it be the switch
    > itself? Is there an easy way to test that theory? Should I just get
    > the right relays and try those? (Are the CDS FAN the right relays?
    > Where can I get them?) I've also read some references in this group to
    > a blower resistor pack on the motor, but it sounds like since the motor
    > won't come on even at highest speed, when the current should flow
    > directly to it, this may not be the culprit.
    >
    > Please help before I do any more damage. I know just enough to cause a
    > blackout in the neighborhood. :-)
    >
    > Thanks in advance,
    >
    > Alex
    >


    You have a volt meter and access to the blower motor so you are in the right
    area. Power to the blower motor passes through a resistor pack that resides
    in or near the blower cage. Since you do not have voltage at the blower
    motor, the next step is to work your way backwards towards the power source.
    Problems with the resistor pack are common causes of blower problems so I
    would check that next. If you look at where power comes into the resistor
    pack, you can follow it out where it goes to the blower. See if there is
    voltage coming into the resistor pack and coming out of the resistor pack.
    If there is voltage to the pack but none coming out, then there is an open
    circuit in the pack. If you are handy at soldering, look for a break
    somewhere in the pack.
    --

    Ray O
    (correct punctuation to reply)



  3. #3
    Danny G.
    Guest

    Default Re: 4Runner blower problems


    "Alex" <gsargucci@netscape.net> wrote in message news:1166546817.433446.237110@i12g2000cwa.googlegr oups.com...
    > Hi folks,
    >
    > I'm trying to troubleshoot a non-working fan on a '91 4-Runner and was
    > wondering if someone can offer some tips. (The fan in question is the
    > inside blower fan/AC.) It no longer comes on. This happens at ALL
    > speeds, includiing the highest. I've checked whatever fuses I could
    > think of and even have given the 'CDS FAN' relays a few wacks with a
    > screwdriver, just in case they got stuck... No luck.
    >
    > I've taken off the glove compartment and gotten to the motor, but am
    > not really sure what to look for there. I've disconnected what appears
    > to be the power supply wire to the motor and, with the fan switch
    > turned all the way up, hooked up a voltmeter to all the terminals,
    > every which way I could think of. I can't seem to register a voltage
    > there. (BTW, should I still expect to read somewhere around 12V DC
    > there, just like I do at the battery?) This seems to imply that
    > there's no power to the motor, which would then rule out the motor
    > itself. However, I'm:
    >
    > 1. Not 100% convinced that I'm measuring voltage in the right place and
    > in the right manner
    > 2. Even if I am, am not sure where to go look for the problem at this
    > point.
    >
    > I've also done my best at trying to measure voltage across the relay
    > terminals (again, CDS FAN #1 & 2, with the engine running and fan
    > switch all the way to ON). And again, I've been unable to register any
    > kind of voltage, but am not sure that I'm doing it correctly.
    > (Measuring across the 'already ON' terminals, not the switched ones.)
    >
    > Can someone offer some ideas to try next? Could it be the switch
    > itself? Is there an easy way to test that theory? Should I just get
    > the right relays and try those? (Are the CDS FAN the right relays?
    > Where can I get them?) I've also read some references in this group to
    > a blower resistor pack on the motor, but it sounds like since the motor
    > won't come on even at highest speed, when the current should flow
    > directly to it, this may not be the culprit.
    >
    > Please help before I do any more damage. I know just enough to cause a
    > blackout in the neighborhood. :-)
    >
    > Thanks in advance,
    >
    > Alex
    >


    If you print #37 at this link it should help:
    http://autozone.com/servlet/UiBroker...3d80161a4e.jsp

    Autozone.com should have a complete repair manual and more for your truck there online and free.

    GL Dan



  4. #4
    Alex
    Guest

    Default Re: 4Runner blower problems

    Thanks Ray. Am about to look at it. One question though: I was under
    the impression that on the highest fan setting, power went directly to
    the motor, bypassing the resistor pack. So, if the motor didn't work
    even on the highest setting, then the resistor pack might not be the
    cause. Or does power go through the pack (but not the resistors) even
    on highest settings?

    If I end up having to look at the switch, is there an easier way to get
    at the sucker, other than taking off all of the panels in front of it?

    Thanks again,

    Alex

    Ray O wrote:
    > "Alex" <gsargucci@netscape.net> wrote in message
    > news:1166546817.433446.237110@i12g2000cwa.googlegr oups.com...
    > > Hi folks,
    > >
    > > I'm trying to troubleshoot a non-working fan on a '91 4-Runner and was
    > > wondering if someone can offer some tips. (The fan in question is the
    > > inside blower fan/AC.) It no longer comes on. This happens at ALL
    > > speeds, includiing the highest. I've checked whatever fuses I could
    > > think of and even have given the 'CDS FAN' relays a few wacks with a
    > > screwdriver, just in case they got stuck... No luck.
    > >

    >
    > I believe that the "CDS Fan" relay is for the condenser fan in the engine
    > compartment and not for the AC/heater fan.
    >
    > > I've taken off the glove compartment and gotten to the motor, but am
    > > not really sure what to look for there. I've disconnected what appears
    > > to be the power supply wire to the motor and, with the fan switch
    > > turned all the way up, hooked up a voltmeter to all the terminals,
    > > every which way I could think of. I can't seem to register a voltage
    > > there. (BTW, should I still expect to read somewhere around 12V DC
    > > there, just like I do at the battery?) This seems to imply that
    > > there's no power to the motor, which would then rule out the motor
    > > itself. However, I'm:
    > >
    > > 1. Not 100% convinced that I'm measuring voltage in the right place and
    > > in the right manner
    > > 2. Even if I am, am not sure where to go look for the problem at this
    > > point.
    > >
    > > I've also done my best at trying to measure voltage across the relay
    > > terminals (again, CDS FAN #1 & 2, with the engine running and fan
    > > switch all the way to ON). And again, I've been unable to register any
    > > kind of voltage, but am not sure that I'm doing it correctly.
    > > (Measuring across the 'already ON' terminals, not the switched ones.)
    > >
    > > Can someone offer some ideas to try next? Could it be the switch
    > > itself? Is there an easy way to test that theory? Should I just get
    > > the right relays and try those? (Are the CDS FAN the right relays?
    > > Where can I get them?) I've also read some references in this group to
    > > a blower resistor pack on the motor, but it sounds like since the motor
    > > won't come on even at highest speed, when the current should flow
    > > directly to it, this may not be the culprit.
    > >
    > > Please help before I do any more damage. I know just enough to cause a
    > > blackout in the neighborhood. :-)
    > >
    > > Thanks in advance,
    > >
    > > Alex
    > >

    >
    > You have a volt meter and access to the blower motor so you are in the right
    > area. Power to the blower motor passes through a resistor pack that resides
    > in or near the blower cage. Since you do not have voltage at the blower
    > motor, the next step is to work your way backwards towards the power source.
    > Problems with the resistor pack are common causes of blower problems so I
    > would check that next. If you look at where power comes into the resistor
    > pack, you can follow it out where it goes to the blower. See if there is
    > voltage coming into the resistor pack and coming out of the resistor pack.
    > If there is voltage to the pack but none coming out, then there is an open
    > circuit in the pack. If you are handy at soldering, look for a break
    > somewhere in the pack.
    > --
    >
    > Ray O
    > (correct punctuation to reply)



  5. #5
    Ray O
    Guest

    Default Re: 4Runner blower problems


    "Alex" <gsargucci@netscape.net> wrote in message
    news:1166557919.785802.279200@i12g2000cwa.googlegr oups.com...
    > Thanks Ray. Am about to look at it. One question though: I was under
    > the impression that on the highest fan setting, power went directly to
    > the motor, bypassing the resistor pack. So, if the motor didn't work
    > even on the highest setting, then the resistor pack might not be the
    > cause. Or does power go through the pack (but not the resistors) even
    > on highest settings?
    >


    I believe that the wiring for the blower passes through the resistor pack
    frame but not through the resistors with the blower on the highest speed
    setting.

    > If I end up having to look at the switch, is there an easier way to get
    > at the sucker, other than taking off all of the panels in front of it?
    >
    > Thanks again,
    >
    > Alex
    >


    According to the pictures on this web site with instructions for installing
    an accessory bracket
    http://www.pro-fit-intl.com/Adobe/TY-70-90.pdf the switch looks like it will
    take less than 5 minutes to get at it.


    --

    Ray O
    (correct punctuation to reply)



  6. #6
    Alex
    Guest

    Default Re: 4Runner blower problems

    Thanks Ray. I got the Climate controls panel off, so it looks pretty
    much like that picture now. The trick now would be to get to the back
    of that panel, in order to get to the switch wiring and take in/out
    voltage reading there... Can't seem to get at it w/o removing the
    clock and the trim panel around it. Arrgghh...

    Another follow-up question about the resistor pack possibility. Is the
    resistor pack upstream or downstream from the blower motor plug (where
    I'm taking the voltage reading). In other words is it like A) or B):

    A) SWITCH --> RESISTOR PACK --> PLUG --> BLOWER MOTOR
    B) SWITCH --> PLUG --> RESISTOR PACK --> BLOWER MOTOR

    Since there doesn't seem to be any power at the PLUG terminals, then if
    it's A), then it might be the resistor pack. If it's B), then it's
    something else.

    Thanks!

    Alex

    Ray O wrote:
    > "Alex" <gsargucci@netscape.net> wrote in message
    > news:1166557919.785802.279200@i12g2000cwa.googlegr oups.com...
    > > Thanks Ray. Am about to look at it. One question though: I was under
    > > the impression that on the highest fan setting, power went directly to
    > > the motor, bypassing the resistor pack. So, if the motor didn't work
    > > even on the highest setting, then the resistor pack might not be the
    > > cause. Or does power go through the pack (but not the resistors) even
    > > on highest settings?
    > >

    >
    > I believe that the wiring for the blower passes through the resistor pack
    > frame but not through the resistors with the blower on the highest speed
    > setting.
    >
    > > If I end up having to look at the switch, is there an easier way to get
    > > at the sucker, other than taking off all of the panels in front of it?
    > >
    > > Thanks again,
    > >
    > > Alex
    > >

    >
    > According to the pictures on this web site with instructions for installing
    > an accessory bracket
    > http://www.pro-fit-intl.com/Adobe/TY-70-90.pdf the switch looks like it will
    > take less than 5 minutes to get at it.
    >
    >
    > --
    >
    > Ray O
    > (correct punctuation to reply)



  7. #7
    Ray O
    Guest

    Default Re: 4Runner blower problems


    "Alex" <gsargucci@netscape.net> wrote in message
    news:1166561023.050169.54300@f1g2000cwa.googlegrou ps.com...
    > Thanks Ray. I got the Climate controls panel off, so it looks pretty
    > much like that picture now. The trick now would be to get to the back
    > of that panel, in order to get to the switch wiring and take in/out
    > voltage reading there... Can't seem to get at it w/o removing the
    > clock and the trim panel around it. Arrgghh...
    >

    Once you get the hang of taking stuff apart, it gets easier. Removing the
    trim around the clock and audio system does not look too difficult, and the
    clock and/or HVAC controls are probably held with 2 orf 4 screws.

    > Another follow-up question about the resistor pack possibility. Is the
    > resistor pack upstream or downstream from the blower motor plug (where
    > I'm taking the voltage reading). In other words is it like A) or B):
    >
    > A) SWITCH --> RESISTOR PACK --> PLUG --> BLOWER MOTOR
    > B) SWITCH --> PLUG --> RESISTOR PACK --> BLOWER MOTOR
    >
    > Since there doesn't seem to be any power at the PLUG terminals, then if
    > it's A), then it might be the resistor pack. If it's B), then it's
    > something else.
    >
    > Thanks!
    >
    > Alex
    >


    I am not real clear on what you mean by "upstream" and "downstream" and I do
    not have a wiring diagram for your truck, but in general, power goes from
    the switch to a relay, then the relay provides higher current power to the
    resistor pack, and then power goes to the blower.

    If the resistor pack has just 1 connector plug, then some of the pins on the
    plug connect the resistors to the power supply (relay) and some of the pins
    on the plug connect the resistors to the load, which in this case is the
    blower motor. A wiring diagram would help identify where each wire and pin
    on the connector leads to. With the fan switch on, I would think that there
    should be power to at least some of the pins on the resistor pack plug.

    If the switch is too hard to reach, look for a relay, fuse, or circuit
    breaker for the heater fan.

    --

    Ray O
    (correct punctuation to reply)



Similar Threads

  1. PLEASE HELP!!!! 91 4runner problem
    By 91HoRunner in forum alt.autos.toyota
    Replies: 2
    Last Post: 12-19-2006, 07:25 AM
  2. Replies: 1
    Last Post: 09-12-2006, 01:25 AM
  3. Replies: 2
    Last Post: 09-12-2006, 01:17 AM
  4. Air Box 91 4Runner
    By scholt77@yahoo.com in forum alt.autos.toyota
    Replies: 0
    Last Post: 09-11-2006, 11:46 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •