AC Air Flow Changes at different speeds 1997 BONN.SE.

[97SEBonnevilleMan]

Last summer I read and followed the EVAP. cleaning article "it did help airflow"
Charged my AC system.Everything is fine!!!!
Lately though sometimes while driving the airflow is greater or less when accelerating only while driving ,not sitting still in traffic.Does the resistor on the firewall have anything to do with this???I have a 1997 Bonn.SE Auto air control.
Last summer I did replace the actuator,vacume lines with the EVAP cleaning process .Matt

[willwren]

First things first, you posted this in the Audio section. I'll move it to the correct section for you.

Secondly, if you have 'auto air' I assume you mean ECC (electronic climate control) with the VF display, and no traditional knobs? If so, you don't have a resistor for fan control, you have a solid-state blower control module. I suspect that isn't the issue though, if your fan changes speeds when commanded. I suspect you have a power (electrical/alternator) issue that is rpm related. Your blower speed may only be an innocent victim of the real problem.

[97SEBonnevilleMan]

Thanks for moving my posts to the right section.
The ECC panel has no knobs
Left side two buttons first one Mode/Auto Button
Left side Temp Button
Right Button Fan Speed Control

While driving only "sometimes"the blower motor sounds the same at any speed but,the air is slower coming out of the vents,during acceleration while changing lanes.I did the Evap. cleaning last summer.

So the alternator could be the problem?

[sandrock]

I have the same issue and I've been fighting it for some time. I needed to replace my airmix actuator anyways because it failed, and I hoped that was also the root of my problem. It wasn't.

And the alternator on mine is good. Blower control module also tests fine voltage-wise, but I am suspecting it isn't putting out enough amperage to satisfy the blower.

EDIT: When I get time, I intend on connecting the fan straight to the battery to see what kind of airflow I get. You could do the same

[anwisdom]

You might check vacuum lines too. The change in airflow could also be the diverter shifting the air around. Start with the vacuum canister in the front passenger bumper area and work back. Usually there or the check valve near the firewall on the passenger side under the hood. Most of the vacuum lines on a 97 probably need replacement any way.

[97SEBonnevilleMan]

1.Last summer I replaced the vacume line from the canister through the firewall into the car.Plus various ones on the motor because of age.

2. I removed the dash replaced the vacume hoses with brand new factory ones Plus the Air Mix Actuator....All new Fact. Parts

3. Maybe the Canister has a crack in it? Located under the battery "did not replace this" replaced all the tubing though last summer.

4.Perhaps the Blower Control Module /on firewall /still org.blower motor though.All speed work and are flowing well to this day.

5.Alt.charging fine proper voltage at all times.

Thanks For everyones input.Matt