Fluctuating AC blower (1 Viewer)

[whodat]

When the AC is on low, it blows at varying speeds. In other words, It will blow on low speed then every few seconds cycle through a high speed. The whole time the light for the low is on. I'm guessing it will do the same with the heat on low. Blower motor going?

 

[RavenTai]

Does it go all the way to high?

mine seams to do something similar, in auto, it seams there are finer/more settings available to the climate computer than the 4 that are available with the buttons, but in low it is a set of low speeds it will not go all the way to high wile still showing low. as it brings up the speed it will eventually move the light to the next button an so on and so forth. Another example is moving the temperature slider slightly the fan speed will change slightly but still light the same button. Seams normal and logical to me.

Is that what you have or something else?

Another thing that may be going on is it may be cycling between re-circ and fresh air for some reason that makes a noticeable change in fan noise and flow.

 

[tarbe]

Mine fluctuates when on auto. Kinda unnerving. I leave it in manual mode for that reason.

 

[parabola]

Mine also fluctuates while in auto mode! But, only when auto has decided to use fresh air rather than recirculating. Drives me nuts.

 

[reffug]

Not having auto mine leaves me quite sane thank you.

 

[tarbe]

Not having auto mine leaves me quite sane thank you.

You gotta have something else going on there

 

[sjcruiser]

On Auto control, the Fresh/Recirc. mode is determined mainly through the ambient temperature AND the cabin temperature setting. Adjust the setting to be a tad colder if you don't want fresh air.

 

[parabola]

On Auto control, the Fresh/Recirc. mode is determined mainly through the ambient temperature AND the cabin temperature setting. Adjust the setting to be a tad colder if you don't want fresh air.

Yeah that does kick it back to recirc, but that doesn't explain why it cycles the way it does. We're talking about hearing the blower cycle up and down about once every 3 seconds or so. It's really annoying and something doesn't seem to be working properly here...

And if y'all's is anything like mine, it has this really bothersome click and squeak when it goes from high to low during this cycling madness. ARGH.

 

[whodat]

Mine does it even when not on auto mode

Seems like the fan is going...but it surges beyond the low setting.

 

[parabola]

Mine does it even when not on auto mode

Seems like the fan is going...but it surges beyond the low setting.

It's not so much being in auto mode as it is being in 'fresh air' mode. 'auto' just so happens to be the only time my truck ever gets in 'fresh air' mode.

Well, at least those are my symptoms.

 

[sjcruiser]

Parabola,

Have you checked if the cabin temp. sensor is clogged or not?

 

[parabola]

Parabola,

Have you checked if the cabin temp. sensor is clogged or not?

No, I have done zero troubleshooting on this issue so far. Guess I could take a look tomorrow....

 

[tbo_cruiser]

bump

Anybody figured this out yet? I have the same issue. The range of variability in the motor speed seems quite wide to me. I have not directly try to compare to see if it gets to high speed, but it has to be close. Very annoying.

 

[jstew0903]

Anyone figure this one out? My 96 LX450 started doing it today. What an annoyance..

 

[flintknapper]

Anyone figure this one out? My 96 LX450 started doing it today. What an annoyance..

Yeah, LX is harder to diagnose because of climate control. LC's just have a resistor and a high speed control relay.

 

[jpoole]

My '97 CE has the auto climate control and I can at least confirm that it has none of these annoying issues you are describing. I've not had to work on it besides cleaning out the hose for the cabin air temp sensor and re-attaching it which only helped the system react better to actual cabin temps.

I'm far from an expert on these but it sounds like there could be an electrical gremlin in the climate control board causing this fan speed oscillation. If the speed is set to low I don't know how a failing motor would cause a speed surge, but maybe that will be explained if it's indeed the problem. I'll be following along to learn more as mine will develop an issue one day I'm sure and I really like the climate control so will want to fix it.

 

[retlaw]

LX450 Air Inlet Servo Issue RESOLVED - https://forum.ih8mud.com/threads/lx450-air-inlet-servo-issue-resolved.1109646/ Not sure if this helps... The 3 second timing mentioned in an earlier post reminded me of my issue.

 

[jstew0903]

@retlaw That sounds like it's probably it. I'm going to tackle it soon and I'll report back. I love having the climate control. Thanks for the link.

Jason