A/C only works on high…STILL

My blower in my 2012 SR5 only works on high. I’ve read a ton about blower motor resistors on here and some say it could be the blower itself.

Well, I replaced my resistor and it did in fact look fried and that worked for less than a month. Now it’s going on and out again. Today I took out the blower out and it was clean as a whistle and the wiring shows no browning or problems. Any ideas on what else it could be?

On high I do notice a low droning noise as well. Just trying to get some air variety and not die of heat stroke. Thanks!

 

Burnt connector, the resistor is only part of the problem.

 

Did you check current draw on the motor?, if it's drawing too much current it will keep killing the resistor.

 

Check the back of your HVAC climate control. 2012 and up had an issue with burning the connector and the pin on the high speed connection side of the climate control due to poor connection at the headunit itself.

 

You may have to replace your blower with a more recent revision. I did much better airflow less noise and no burnt resistor.

The switches for the climate control may be burnt up and need replacement also.

For the resistor did you go new OEM or aftermarket or used?

 

Yeah check this OP. Went through it with my Jeep TJ. Fan was working fine, but was drawing too much current. Replaced it 3 years ago and never had an issue since.

 

Heed the advice of the above posters. For me personally, the result would be a new resistor and blower. Welcome to TW.

 

Pull the resistor connector and look for melting and a brown burn streak. Sometimes you can put the blower on medium and wiggle the connector and have it come on to prove the issue. If its not yet burnt, you may need to put a cheap Harbor Freight dental tool down in the connector and spring the contacts out so they make contact with the resistor. This is all very common.

 

Replace the pigtail. It’s usually the culprit more so than the resistor.

 

This is the only comment in this thread that hits the mark.

The resistor very rarely burns out. Most of the time, people replace the resistor and it works again because the contacts are new. However, the real issue is poor contact between the harness and the resistor terminals. As a result, you get arcing and this eventually toasts the harness and causes the contacts to get dirty.

To fix it, go in and unplug the harness and remove the resistor. Look at how the terminals plug in and which socket is discolored. Check how the two fit together and bend the terminal on the resistor in the direction of the socket's contact. You are looking to have the terminal put ample pressure on the contacts in the harness. You can also use a fine tool to bend the socket's contact a little too (this will really help). After that, clean all contacts with electrical contact cleaner or alcohol. Let it dry and then plug it back in. Should work fine.

Context: I've been using the same blower motor resistor for 12 years and I live in Texas so I'm using my AC all the time. I've done this about 4 different times over the years and it works 100% of the time.