Blower won't turn off of high

Hi I just bought my car yesterday and my blower fan will nt turn off of high or even turn off. Does anyone have any suggestions as to how to go about finding and fixing this issue?

Welcome to the Fest.

I am not all that great with electrical issues, but this sounds like the blower relay may have gone bad and is allowing continuous contact for electricity to flow. I would suggest that you replace the relay.

If you don’t already have it, you need to get the Bentley manual, either in hard copy or download it. You can search this forum and fine a link to where you can download it for free.

If you get it, go to page 610-1 and you will see a diagram of the front power distribution box which is located by the shock tower on the driver’s side (assuming a U.S. car). It should be relay #4. If you don’t have the Bentley, then pull the cover from the box and it should be the relay on the far right in the row of relays that is next to the row of fuses.

Good luck and let us know the outcome.

It could be the blower motor resistor, which is located above the gas pedal, behind the panel on the right side. A search will get you to a nice detailed DIY of replacement of the resistor, but I also recommend picking up a Bentley, as Steve mentioned above. Good luck and please post back.

Sent from my Droid Incredible

Originally Posted by goosefoot33

It could be the blower motor resistor, which is located above the gas pedal, behind the panel on the right side. A search will get you to a nice detailed DIY of replacement of the resistor, but I also recommend picking up a Bentley, as Steve mentioned above. Good luck and please post back.

Sent from my Droid Incredible

I thought about the resistor, but since the blower was not shutting down, even with the car turned off, I was thinking something had failed causing constant voltage to be supplied to the blower. I wasn't sure if a failed resistor could do this since, in my infantile understanding, the resistor simply reduces voltage as it goes through it. I hope the OP gets it figured out and gets back to us with the solution.

Ok well the fan does turn off when the key is off. I replaced the relay and that was not the issue. I believe it may be the resistor. It has also caused my blower motor to wear out. This car has problems because I'm fairly sure my oil pressure sensor is out as well.

Is the defog/demist turned on? I replaced the "sword" in my car 7 or 8 months ago (because the fan would only work on high, but I could still turn it off) and when I had it all put together again it was on high all the time. By the time I figured out the the defog system caused the fan to run on high (I don't think this is how the system is supposed to work, but I don't use defog much right now so it doesn't bother me yet) the fan blew a bearing and I had to replace it as well. (It was already on it's way out)
Let us know if this helps.
I am not intending to threadjack, but can anyone confirm that (if my guess happens to be correct about the OP's defog system being the cause) the defog is working as designed or malfunctioning?