Air Conditioner Fan Doesnt Work

[Eddiep]

Hi,
I own a Honda NSXT 1995 model. After reading all the posts on faulty air conditioners I just had the all the capacitors changed on the control unit circuit board, but the fan still doesn't work. With the vents and the clock out of the dash, as i am driving, I can feel cold air coming through the hole but when i stop so does the air flow, The fan simply isn't working. Anyone got any clues why the fan doesn't work or where in the car I can i find the fan unit, so i can test that on its own, as it may or may not be faulty. Need this working quickly as we are having days of 36 to 43 degrees Celsius here in Western Australia at the moment and without the air conditioner working the car is a hot box.
Cheers Eddie

 

[Miner]

Verify that the fuse for the blower is good.
Check for 12 vDC at the connector of the blower.
Early model NSXs had an issue with the blower and it would cause the fan to run only at high speed, but you seem to have a lack of any fan motion. Make sure you rotate the fan knob to full speed to make sure it isn't the blower transistor.
If you are handy, I am pretty sure you can apply 12 vDC directly to the blower motor at the connector and if the fan turns, look elsewhere. If it doesn't turn, I think you have a bad motor. On the bright side, it is easy to replace.

 

[Old Guy]

First off, if you don't already have it down load a .pdf copy of the service manual. You are going to need it if this is less than a simple problem.

Here is the schematic for the blower motor circuit. As suggested by Miner, check the #28 fuse to make sure that it has not opened. Next, check the blower relay. Remove the relay from its socket and check for burning on the relay pins and damage to the wiring in the socket. Test the operation of the relay. If you are not familiar with electrical devices, the service manual will show you how to test the relay. It will also give you a location - be aware that that I seem to recall that it moved around during the production run.

If the relay works the next test is with the key in the run position, take a wire and short the black/blue wire from the blower motor to ground. This should force the blower motor to run at high speed. Two possible outcomes:

1) If the blower motor does not operate then the motor has failed or the wiring to the motor has failed. The blower motor is accessed from the front hood area. The service manual describes the location and access to the connectors. Test the motor as described in the service manual. If the motor has failed then replacement is in order. If the motor runs, then you have a wiring problem.
2) If the motor does operate then the power transistor has failed or the CCU repair was not successful. If the power transistor has failed, the blower should still operate on the max speed position. If the CCU repair failed likely nothing will happen (did you run the CCU through its self test procedure?)​