I am having an issue with my car was wondering if anyone knew or had the same issue with their car. The fan one day while driving turned on high and would not shut off. The controls move and respond but the fan is stuck on high! I thought blower motor resistor? I disconnected the fan so it wasnt on high blasting out hot air!

 

Possibly the blower motor relay? stuck ON? pull (remove) to test.

I have an RDX, so not sure which would be the correct relay for your TL. Did the blower motor continue to run after shutting down the engine (ignition OFF)?

I am assuming that you mean the blower motor for interior air, not the A/C condensor fan motor, AKA radiator fan motor?

 

Looks like a new 79330-S6M-941 TRANSISTOR, POWER $54.58 $40.94 will fix the problem:
https://acurazine.com/forums/3g-tl-problems-fixes-114/c-wont-turn-off-785932/

Just an FYI-Rock Auto has the part listed:
STANDARD MOTOR PRODUCTS Part # RU348 {#79330S6M941} Intermotor $32.79
Intermotor is a brand of Standard Motor Products that has been traditionally sold in Europe
and is now available in the US. Alternate/OEM Part Number(s): 79330S6M941

Here's the code for an additional 5% Discount D3D5BBA44193 Expires: 06/20/2013

 

I agree with turbonut, transistor is usually the cause for problems like this.

FYI: the transistor is what basically controls the speed of the blower motor by using voltage to regulate the power ouput. So when it only works on HIGH or a single speed,it's usually the transistor.

 

Thanks so much I appreciate it! I ordered the part should be arriving tomorrow and i will switch it out then! We will see one mechanic told me it was the control module for the a/c unit and quoted $500. Hopefully its the resistor!

 

Switched out the blower motor resistor nothing happened now the fan isn't even on at all. Put the old one back in and it's still stuck on high! Any solutions?

 

If I were you, I would check the relay first for sanity sake. Then I would start probing the voltage outputs of the transistor to determine if it is providing the correct voltages at different speed settings. It's still possible that it's the issue, maybe you got a defective part. Put your OEM transistor back in and measure the voltages. At least that will narrow the issue down since based on your update, we still don't really know the root cause. That's why I avoid slinging parts at stuff, even if it's just $30.

 

FYI Another episode of blower motor transistor failing. Fan went to high speed suddenly and could not turn down. AC would not kick in but heat worked fine, and climate control buttons were responsive to all other commands, except AC. I hit this forum, did a search, and pulled the panel under the glove box. Got transistor unit out, and swapped in the same unit from my other TL

Turned the ignition key on and voila the fan did not immediately go on high, and everything else tested ok, and compressor clicked on and cold air again.

The part is $46 at Autozone and O'Reilly.

I had tested the unit with a multimeter and the thermal fuse was ok, resistors were not burned, so that leaves the transistor as the suspect. Now something caused it to go, right?