2004 Toyota heater fan speed issues

I have a 2004 Toyota Tacoma. Out of the blue, the heater fan quit working - no previous issues. No blown fuses found. Then with no repair, the lowest two speeds operated, alhtough not the highest two. After reading many posts, it appeared to be the resistor. I just replaced it, and no change - still only the lowest two speeds and no highest two speeds.

I've seen many posts, alhtough nothing directly on point. If there is one out there, my apologies. Does anyone have any direction to check and/or repair?

 

Not sure if it's the same issue, but my Celica fan just stopped working, I spun the knob back and forth a bunch of times and it's starting working. I must've loosened up some corrosion somewhere doing that.

 

I just tried moving the switch back and forth, and no luck. Thanks, it was definitely worth a try.

 

Mine has been doing the same for a couple years. Changed the resistor (from auto parts store, not OEM) and still doing it. I think I need a new motor but I'm just taking whatever speed(s) it gives me until it goes out (not my daily driver). Curious to see what you find out.

 

I would look at the switch they do wear and quit working. The harness to the resistor as well.

Since you already changed the resistor unless the resistor is just poor quality and not making good contact.

As long as the motor works at all the problem is else where.

Good luck

 

All, I am starting to look at the control panel. I suspect the switch you may be referring. I did notice today, my heat is running at full temperature and changing the temp at the panel does not change the temp. This might explain both the fan speed and the temperature failing at the same time.

I'll post the solution, once I have one.

Any thoughts are appreciated. Thanks!

 

If any of this helps:

*** Lo and M1, power at resistor port 3 (I think three anyway) - speed does change between Lo and M1
*** No power at with M2 or Hi
*** Heater relay has power at 1 and 5 all settings

Should I not have power at the resistor port for M2 and Hi???
The ports look good, with no burning noted.

I am beginning to think it may be the control panel switch.

Thank you very much for anyone who can shed some light on this.

 

You should have system voltage at the resistor to match the settings on your switch .

As you move your switch every setting should show at the resistor.

When the switch and harness are working correct .

 

I would check the blower motor resistor. They get old and stop working completely or just low setting works.

 

Nope switch controls the ground side through the resistor, blower gets full power on pin 1 (Black/White) from the HEATER Relay when the switch is on and ground goes through switch then through the resistor except low goes directly through the resistor.

 

Thanks for the correction I make mistakes going from memory because the EWD`s are in the shop.

 

No problem.
Most HVAC blowers are controlled on the ground side from what I've seen.

 

a squirt of electrical contact cleaner ? before you start taking the dash apart

 

I’m having an issue.
Low blows low. 2nd up blows. 3rd up blows lower than low, and high blows.

 

On cable controlled HVAC panels
Pretty easy to disassemble/clean/re-install
But electronic ones….same premise, lil more difficult thou
Not exact but you can see the issue

https://m.youtube.com/watch?v=NhKHH2W7bwg

these HVAC controls are readily available from LKQ vendors online too(car-part.com)
Not horribly expensive
GL

 

so do you think it’s just the switch?

 

It’s a good guess
Mainly bc some speeds work, others do not…..on same control knob

at very beginning of video
Showed easy fix tht worked for a time

 

I am not sure what to think. After a cold spell and rain, I rechecked the resistor connection this evening. The blue and black wire, port #1 had power on low, M1, and M2. No power on high, although high fan actually worked. Upon plugging back up, all four settings were operating.

Does anyone have any thoughts??? I am not complaining, although seems odd to just start working again.

 

Many times I have encountered just taking things apart, maybe cleaning and then putting back together…..rectifies the issue……for a time
Be proactive and search for a cheap used HVAC panel in the meantime!

 

In the end, I do believe it is the HVAC panel switches. Yesterday, the High quite working, although with some some jiggling, it started to work again. I tried twisting/jiggling before and it didn't work. I do feel confident it is the panel switches.

Thank you everyone for the contributions!