xakep

I checked the blower motor unit by connecting power to it directly. It blows pretty good .
Next I checked if it gets any power. When I disconnect the power plug from the blower motor unit the multimeter shows 12.5VDC, whether ac is on or off. When I connect the plug back to the blower unit the meter shows 0 to very small Volts, whether AC is on or off. The fuses 9 and 21 are fine. I was not able to trace where the wire goes exactly. Can anybody tell me where those wires go or what should be the next checkpoint? I think that the blower motor power transitor is located outside the blower unit, does anybody know where it is located?

thanks

poltergeist

The white/blue wire at the blower motor is switched "hot" with the ign in "on" position by the blower motor relay in the underhood fuse box. If you've got battery voltage at the blu/white with the key on, and the motor runs by jumping ground to the blue/black wire, then there's a problem in the blower speed control side of the circuit. The blue/black wire is a variable ground from the blower transistor to control fan speed. The transistor is mounted in the ducting to the left of the blower motor. There's a procedure to test it, but it requires removing pins from the connector......long story short, if the motor runs with ground jumped to the blue/black, 99% of the time you've got a failed blower transistor.

BTW: Fuse 30 in the underdash box and 21 in the underhood box are the only two fuses related to the blower motor circuit.

xakep

Thanks a lot !!! You are right, when I connect the blue/black to the ground the blower runs. I looked to the left of the blower motor, but could not locate the transistor holder (I assume it will be concealed in some sort of a plastic box.)

Please help to find where this transistor is mounted and where from I should purchase it a new one.

poltergeist

It's mounted into the air duct between the blower motor and the AC evaporator, maybe half way between the blower and the center console. It uses the airstream in the duct to cool it. Has a 4 pin connector with blu/yel, blk, blu/red and blu/blk wires in the connector.

Pretty much have to buy it from Acura....either your local dealer or one of the online venders. I doubt anyone makes an aftermarket replacement part. I guess you could try Ebay, but buyer beware........

xakep

THANKS A LOT!

I found that transistor and ordered it from oemautoparts. $48 plus shipping. I hope that is the only thing that I need to replace.

dcslim

I'm having the same problem with my '04 TSX. For those of us who aren't technically inclined, what's the easiest way to get power to the blower motor to check to see if it's working? Simple instructions would be greatly appreciated. Thanks in advance.

agustin67

Anyone have a diagrham or pictures?

TexasHonda

You don't jumper power to the blower, but ground to the blue/black wire.

Blower is always powered, and ground resistance is modulated by power transistor to control blower speed. When you jumper ground to the blu/blk at the motor you bypass the power transisotor. Blower will run at full speed. If this doesn't make sense you need to get someone who does understand.

good luck