Help!! I have been fighting with my 2006 Honda Accord's blower motor for the last few months; it is stuck on high speed. It started when I replaced a noisy blower motor with a new aftermarket model and aftermarket resistor. All was well for about two months and then the crap hit the fan; no pun intended.
In effort to fix after initial replacement noted above, I have:
-I replaced the resistor with a Duralast resistor from Auto Zone and the fan worked for two days and then the fan was stuck on high.
-Took it to my mechanic who said the fan was OK; not drawing too much power, wiring is in good shape, etc. He replaced the resistor with another Duralast resistor from Auto Zone and it worked for only two days. Mechanic said to buy OEM resistor from Honda to fix problem if it broke again. He said that he has done all he can do.

The only other solution, that I can think of is to try and replace the blower motor with an OEM blower motor (on order) and a new resistor. I do not know what else to do as I do not want to keep throwing parts at the problem. I have a sneaking suspicion that the current fan motor is drawing too much power; despite what my mechanic stated.
If anyone has any suggestions, it will be REALLY appreciated.

Chris A.
2006 Honda Accord VP AT
130,000 miles

 

The common diy thread on top of the gen tech help section has a link on how to check HVAC codes for your car. It is easy to try and may help identify a problem.

Is there any chance that you have the original resistor for your car? I'd try reinstalling it to see if this fixes the problem.

The wiring or possibly the HVAC may cause this issue. I'd inspect the wiring to the resistor and blower motor for any obvious damage.

 

Based on the way the circuit works, it will unlikely be due to the blower motor. Running at high speed only is indicative of a faulty blower motor transistor. Heat and/or not as robust electrical parts may be what is causing aftermarket transistor to fail. Things to check are clogged filter impeding air flow, etc.

With the ignition turned ON, the positive side (+) of the blower motor wiring is always hot if the blower motor relay is working properly and fuses are good, it just needs the negative ground (-) source through the blower motor power transistor. The speed of the motor is thus controlled by varying the ground via the power transistor.