93 accord radiator fan not on
#1
93 accord radiator fan not on
93 honda accord, automatic. The radiator fan is not coming on when engine gets hot.
If I turn on the air conditioner, both fans work.
If I disconnect the 2 pin thermoswitch and short the harness connectors, the fan does not work. However, If I leave the harness connectors shorted and turn the car off, the fan comes on (!?!), and immediately shuts off if I pull the short wire.
With the thermoswitch harness still shorted, Pulling the relay labeled "cooling fan" in the fuse box does nothing, no clicking. Replacing the relay with the one next to it (power window), which is same part number and nothing happens either.
Any thoughts???
Help?!
THanks,
Tony
If I turn on the air conditioner, both fans work.
If I disconnect the 2 pin thermoswitch and short the harness connectors, the fan does not work. However, If I leave the harness connectors shorted and turn the car off, the fan comes on (!?!), and immediately shuts off if I pull the short wire.
With the thermoswitch harness still shorted, Pulling the relay labeled "cooling fan" in the fuse box does nothing, no clicking. Replacing the relay with the one next to it (power window), which is same part number and nothing happens either.
Any thoughts???
Help?!
THanks,
Tony
#2
Originally Posted by aw_wolfe
93 honda accord, automatic. The radiator fan is not coming on when engine gets hot.
If I turn on the air conditioner, both fans work.
If I disconnect the 2 pin thermoswitch and short the harness connectors, the fan does not work. However, If I leave the harness connectors shorted and turn the car off, the fan comes on (!?!), and immediately shuts off if I pull the short wire.
With the thermoswitch harness still shorted, Pulling the relay labeled "cooling fan" in the fuse box does nothing, no clicking. Replacing the relay with the one next to it (power window), which is same part number and nothing happens either.
Any thoughts???
Help?!
THanks,
Tony
If I turn on the air conditioner, both fans work.
If I disconnect the 2 pin thermoswitch and short the harness connectors, the fan does not work. However, If I leave the harness connectors shorted and turn the car off, the fan comes on (!?!), and immediately shuts off if I pull the short wire.
With the thermoswitch harness still shorted, Pulling the relay labeled "cooling fan" in the fuse box does nothing, no clicking. Replacing the relay with the one next to it (power window), which is same part number and nothing happens either.
Any thoughts???
Help?!
THanks,
Tony
#6
Which thermoswitch are you shorting (in your first post)?
The one on the thermostat housing is responsible for switching the fan while the engine is running. The other one (in upper radiator hose neck?) is responsible for switching the fan after turning off the engine.
The fan timer module is responsible for deciding which fan switch to use.
The one on the thermostat housing is responsible for switching the fan while the engine is running. The other one (in upper radiator hose neck?) is responsible for switching the fan after turning off the engine.
The fan timer module is responsible for deciding which fan switch to use.
#7
JimBlake,
Thanks for the info. Yes, you are right, I did not realize until yesterday that there were in fact 2 different Thermoswitches A & B. I've 'hard' shorted the Thermoswitch A to keep both fans on while the car is running until I can pull out the thermostat and thermoswitch to test them. Any issues with doing so short term?
Anyway to determine which might be bad (thermostat or thermoswitch A)while still in car?
THanks again,
TOny
Thanks for the info. Yes, you are right, I did not realize until yesterday that there were in fact 2 different Thermoswitches A & B. I've 'hard' shorted the Thermoswitch A to keep both fans on while the car is running until I can pull out the thermostat and thermoswitch to test them. Any issues with doing so short term?
Anyway to determine which might be bad (thermostat or thermoswitch A)while still in car?
THanks again,
TOny
#8
Whenever you're driving at least 20 mph, you don't need fans at all. So if your engine temperature is OK while you're driving around (especially climbing big hills), then your thermostat is OK. If your thermostat sticks open, then your engine will take forever to warm up.
The only time you need the fans is when you're going real slow (or stopped) so there's no air going naturally thru the radiator.
So now, with the switch A shorted, is your engine temperature gauge behaving normal? If so, your thermostat is OK. The only downside to shorting this, is how quickly you'll wear out the fan motor. (You could use a toggle switch.)
Finally, remember that the fan switch isn't supposed to come on at the same temperature as the thermostat. Your gauge will have to move up (above 1/2 scale) before the fan switches on. As long as it doesn't go very close to the top (red) part of the gauge.
The only time you need the fans is when you're going real slow (or stopped) so there's no air going naturally thru the radiator.
So now, with the switch A shorted, is your engine temperature gauge behaving normal? If so, your thermostat is OK. The only downside to shorting this, is how quickly you'll wear out the fan motor. (You could use a toggle switch.)
Finally, remember that the fan switch isn't supposed to come on at the same temperature as the thermostat. Your gauge will have to move up (above 1/2 scale) before the fan switches on. As long as it doesn't go very close to the top (red) part of the gauge.