AC/heater blower motor not working
#1
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Location: mesquite, tx
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AC/heater blower motor not working
I was troubleshooting my AC in my 91 4runner (22re), I disconnected my compressor just to check the voltage, when I plugged it back in the blower motor, witch was working before I stared did not work anymore. I checked the fuse it was ok, what else can I check?
#2
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You won't measure any voltage at the compressor until the air conditioning is turned on and is trying to engage the magnetic clutch. The compressor on your A.C. is a different circuit from your blower motor and it may be just a coincidence that your blower stopped working when you pulled the connector off of the compressor.
Most of the time when a blower motor stops working it's the blower resistor, they either short to ground or burn open. Does the blower work on any of the speeds? you should find it not far from the blower motor. The resistor has a 4 wire plug and it is mounted in the heater ductwork, because it is cooled by the moving air.
There are 2 fuses involved in the blower motor circuit, 40A. Heater runs the blower motor, but the 10A. Gauge fuse feeds the coil side of the Front Heater Relay. If the coil doesn't get powered up the relay contact won't close and the power from the 40 amp heater fuse won't get to the blower motor. If either of those is blown your blower won't work. Did you check them both?
Most of the time when a blower motor stops working it's the blower resistor, they either short to ground or burn open. Does the blower work on any of the speeds? you should find it not far from the blower motor. The resistor has a 4 wire plug and it is mounted in the heater ductwork, because it is cooled by the moving air.
There are 2 fuses involved in the blower motor circuit, 40A. Heater runs the blower motor, but the 10A. Gauge fuse feeds the coil side of the Front Heater Relay. If the coil doesn't get powered up the relay contact won't close and the power from the 40 amp heater fuse won't get to the blower motor. If either of those is blown your blower won't work. Did you check them both?
#4
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Sorry for not replying sooner. The 40 amp heater fuse and the front and rear relays (also the AC condensor fan relays) are located in Junction Block #3 under the right kick panel. The 10 amp gauge fuse is in Junction Block #1 under the left kick panel.
Go to the sticky section of the 86-95 forum, there is a link to the Toyota FSM 90-94. It's got all of the wiring diagrams.
Go to the sticky section of the 86-95 forum, there is a link to the Toyota FSM 90-94. It's got all of the wiring diagrams.
Last edited by Hadmatt54; 05-26-2010 at 03:36 PM.
#5
I ran into this exact same problem today. I removed the whole a/c system (everything under the hood, nothing under the dash) from my pickup, and my blower motor no longer works (It did the day before). I will check the fuses tomorrow and see if they may have blown somehow. My battery was disconnected when I remover the a/c, so I am at a loss for what could have caused this to happen
Last edited by bossler; 07-01-2010 at 07:14 PM.
#6
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Any familiarity with newer than '95's. I have a 99 taco an the blower has stopped. Not suddenly though. over the last year it would be fickle and sometimes run without hesitation. other times it would only run after a while of driving, and usuallu always after up to speed on the freeway, like it needed airflow to jump it. now it is just dead.
However, the motor runs with direct current. the resister tested good and now back testing the control center. I seem to have found a lack of continuity in the A/C switch ON posistion, though dont know why that would keep it from runing if the A/C wasnt even on???
Am I on the right track? going in for the blower speed switch continutuy test, its deep in there. Or could it still be the motor and it only was turning do to the direct current amps??
However, the motor runs with direct current. the resister tested good and now back testing the control center. I seem to have found a lack of continuity in the A/C switch ON posistion, though dont know why that would keep it from runing if the A/C wasnt even on???
Am I on the right track? going in for the blower speed switch continutuy test, its deep in there. Or could it still be the motor and it only was turning do to the direct current amps??
#7
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I'm not familiar with above 95, but for below 95; by applying 12v directly to the motor you have verified that the motor is ok! You have also stated that the resistor tests to spec, so you either have a bad switch or bad relays. The AC is powered by the front heater relay, so the blower does not need a functioning AC system to work. I said relays because there is of course the heater relay, but the power for the coil side of the heater relay comes through the integration relay. Whether or not your 99 is like this I can't say, but if it is this will give you other troubleshooting paths. However, your best bet is to put out a request on this site or other BBS sites for someone to send you a scan of the heating/ Ac section of the FSM or try and hunt down an FSM for your vehicle.
Good Luck!
Good Luck!
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#8
Blower resistor
You won't measure any voltage at resistor has a 4 wire plug and it is mounted in the heater ductwork, because it is cooled by the moving air.
There are 2 fuses involved in the blower motor circuit, 40A. Heater runs the blower motor, but the 10A. Gauge fuse feeds the coil side of the Front Heater Relay. If the coil doesn't get powered up the relay contact won't close and the power from the 40 amp heater fuse won't get to the blower motor. If either of those is blown your blower won't work. Did you check them both?
There are 2 fuses involved in the blower motor circuit, 40A. Heater runs the blower motor, but the 10A. Gauge fuse feeds the coil side of the Front Heater Relay. If the coil doesn't get powered up the relay contact won't close and the power from the 40 amp heater fuse won't get to the blower motor. If either of those is blown your blower won't work. Did you check them both?
It's the only 4 wire plug I see coming from the blower area. It is a plastic box 1 inch square .
Can someone send a picture??????
#9
I have a 1993 Toyota Pickup SR5. The AC and blower/fan have stopped working. When I turn the fan control from off to any on position I can hear the relay click. Unplugging the two wire connector from the fan I measure ~6 volts when on. If I put 12 volts to the blower it runs at full speed. I also noticed with the fan wire unplugged, if I turn on the AC the little light blinks once very briefly. My guess is the AC may work fine if the blower is working. So what is causing my blower to only get ~6 volts in any on position instead of 12 volts and how can I fix it? Any ideas what might be wrong?
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