1996 Corolla. Bought car a week or so ago and it had no A/C Condenser or dryer installed so since I live in MI and this is my daily beater car, I pulled everything off. (Compressor, bracket, tensioner, lines, evaporator, etc.) The car has two fans because it is an A/C equipped car. According to the Haynes manual the passenger side fan (front of radiator-push) is for when the A/C is running. since I disconnected the harness on the line, it runs constant when the car is turned on. Should I remove this 2nd fan assembly or leave it alone? Is there a way to daisy chain the wiring into the other fan so they run in unison?
Removed all A/C equip now fan runs constant
- Thread starter dwcopple
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That's kind of weird. Can you remove harness at the motor itself? Sounds like there's a relay somewhere between where you disconnected and the fan.
I would not run the two fans together; the power surge when they both kick in/out simultaneously will be substantial.
My 89 mazda 323 had port-installed AC to get around some tariff (?) and it had a condensor slightly offset horizontally from the radiator and its own pusher fan. The engineer in me liked how the two systems were divorced.
I would not run the two fans together; the power surge when they both kick in/out simultaneously will be substantial.
My 89 mazda 323 had port-installed AC to get around some tariff (?) and it had a condensor slightly offset horizontally from the radiator and its own pusher fan. The engineer in me liked how the two systems were divorced.
Toyota often uses a system where there must be power to the coil of a relay in the fan circuit to keep the engine cooling fan OFF. It's a failsafe. If the relay fails, the fan stays ON so the engine will not overheat because of a dead relay. You have to track that relay down amd get power back on it. That will keep the fan OFF until the engine coolant sensor closes for high water tempeture. That sensor is usually at the bottom corner of the radiator. If you UNplug it the fans come ON. Another failsafe. If it quits working, the fans stay ON rather than NOT engaging when the engine is hot. Yes I know it sounds backward, but is is a failsafe. Camrys are wired that way as well. Once you get the engine fan working properly, you can just splice the other fan in parallel. I am sure the relay can handle more than one. Some circuits run BOTH fans for either AC condenser cooling OR high engine heat. They run them in SERIES for low speed and parallel for high speed. You have probably removed more fan wiring than you should have. No big deal, though.
Originally Posted By: HerrStig
Toyota often uses a system where there must be power to the coil of a relay in the fan circuit to keep the engine cooling fan OFF. It's a failsafe. If the relay fails, the fan stays ON so the engine will not overheat because of a dead relay. You have to track that relay down amd get power back on it. That will keep the fan OFF until the engine coolant sensor closes for high water tempeture. That sensor is usually at the bottom corner of the radiator. If you UNplug it the fans come ON. Another failsafe. If it quits working, the fans stay ON rather than NOT engaging when the engine is hot. Yes I know it sounds backward, but is is a failsafe. Camrys are wired that way as well. Once you get the engine fan working properly, you can just splice the other fan in parallel. I am sure the relay can handle more than one. Some circuits run BOTH fans for either AC condenser cooling OR high engine heat. They run them in SERIES for low speed and parallel for high speed. You have probably removed more fan wiring than you should have. No big deal, though.
I have removed no wiring whatsoever yet. The fan is on because the harness that hooked into the AC lines is unplugged now. I will look into wiring together. Keep the ideas coming!
Toyota often uses a system where there must be power to the coil of a relay in the fan circuit to keep the engine cooling fan OFF. It's a failsafe. If the relay fails, the fan stays ON so the engine will not overheat because of a dead relay. You have to track that relay down amd get power back on it. That will keep the fan OFF until the engine coolant sensor closes for high water tempeture. That sensor is usually at the bottom corner of the radiator. If you UNplug it the fans come ON. Another failsafe. If it quits working, the fans stay ON rather than NOT engaging when the engine is hot. Yes I know it sounds backward, but is is a failsafe. Camrys are wired that way as well. Once you get the engine fan working properly, you can just splice the other fan in parallel. I am sure the relay can handle more than one. Some circuits run BOTH fans for either AC condenser cooling OR high engine heat. They run them in SERIES for low speed and parallel for high speed. You have probably removed more fan wiring than you should have. No big deal, though.
I have removed no wiring whatsoever yet. The fan is on because the harness that hooked into the AC lines is unplugged now. I will look into wiring together. Keep the ideas coming!
I just went in the garage and the sensor that was on the A/C line unscrews, so I took it off and plugged it in the open harness in the engine bay. The fan is off now, but since it will never see what it needs to trigger the fan to turn back ON how can I make it so it can be controlled by the now defunct A/C button on the dash or some other switch?
You need real schematics, not the junk that Haynes or Chilton's provides.
HerrStig sounds right on.
And yes, you can wire the fans to be on together, but maybe a bigger fuse or heavier duty relay will be needed for the increased current draw.
It depends on how crafty you are in hooking them up,
And yes, you can wire the fans to be on together, but maybe a bigger fuse or heavier duty relay will be needed for the increased current draw.
It depends on how crafty you are in hooking them up,
The advice given is correct. If the PCM senses no conductivity in anything related to AC or cooling it will trigger the fans all the time to be sure the engine is cooled. Note that AC high side pressure and trans temp also trigger the fans in most cars, not just temps. Many cars follow the strategy HerrStig noted above.
My car runs great on one fan only, you just get a wider swing in temps. I'm sure with one fan you're golden with no AC load.
My car runs great on one fan only, you just get a wider swing in temps. I'm sure with one fan you're golden with no AC load.
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Originally Posted By: dwcopple
ok, thanks. I plan on removing it on Tuesday.
I'd leave it on there, what happens if the ONE fan you leave on quits? They don't weigh that much.
ok, thanks. I plan on removing it on Tuesday.
I'd leave it on there, what happens if the ONE fan you leave on quits? They don't weigh that much.
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