Better AC with different size pulley?

[KansasOBS]

I haven't looked at the diagrams, but I'm guessing the high is straight 12v to the blower motor. Although I don't currently have air working in my truck, I remember these even being new didn't pump out that much. Kind of wonder if GM didn't keep the blower speed down, to reduce cabin noise.

I used the heat this last winter, and it seemed to be doing alright, but the system also came completely apart, new evap, etc. I'm not sure if it moves as much air as my '01 F150 though, and it is loud.

Aside from possible difference in fan size, pitch, and blade width, probably the only thing to get these to move more air would be a motor that's a higher KV.

Technically if I person could open one up, and remove a few turns of winding, it should increase the motor RPM. Or find a different motor which has a higher KV. There isn't a lot of data to compare components though. Person could check with a meter.

I don't suspect any of this info will really be of any help, also not an electrical engineer. Just thought I'd throw it out there.

 

[HotWheelsBurban]

I haven't looked at the diagrams, but I'm guessing the high is straight 12v to the blower motor. Although I don't currently have air working in my truck, I remember these even being new didn't pump out that much. Kind of wonder if GM didn't keep the blower speed down, to reduce cabin noise.

I used the heat this last winter, and it seemed to be doing alright, but the system also came completely apart, new evap, etc. I'm not sure if it moves as much air as my '01 F150 though, and it is loud.

Aside from possible difference in fan size, pitch, and blade width, probably the only thing to get these to move more air would be a motor that's a higher KV.

Technically if I person could open one up, and remove a few turns of winding, it should increase the motor RPM. Or find a different motor which has a higher KV. There isn't a lot of data to compare components though. Person could check with a meter.

I don't suspect any of this info will really be of any help, also not an electrical engineer. Just thought I'd throw it out there.

The blower motor I replaced last year in my crew cab moves more air than the original one did(but it was pretty well wore out after being in the truck for 27 years!). It makes a bit of noise on High, and the #3 speed, but I also didn't replace the rubber cover over it. At the time, I would've had to pull the glovebox out to put it back on, and I wasn't 100% sure the motor would fix it. And I was replacing it in the O'Reilly's parking lot, August in Houston, I need my AC to work!
I would like to have more airflow especially to the back seat(since there is only the middle dash duct that faces back there!). But I know the HVAC box under the dashboard could use a reseal job. Just not interested in yanking the dash to get to it....

 

[99xcss4]

do the small vents on the floor help at all my former friends extended cab has them and I think our 3500 has them as well or do they only work with the heater and I agree with the post you have made a few times saying that the crew cab should have got the roof vents like the suburban or at the very least it should have been a option

 

[1998_K1500_Sub]

Anyway, help with the blower???

Like like the guys do with the headlights or the boom-boom stereos... install heavier wiring.

Get out a voltmeter, measure across the motor on high, then do the same across the alternator and see how much voltage difference there is between the two. If there's even 1V of difference, you can get some improvement.

Try this: Get heavy wire (jumper cable? 8ga?), run a lead from the alternator (preferably, or battery otherwise) to the fan motor, and another lead from the blower motor "ground" to the engine block / alternator (preferably, or battery otherwise).

With the engine running, see how the blower performs. Repeat the voltage measurements, they should be almost identical at the motor as at the alternator (if not, use heavier wire and try again).

If the blower improvement's worthwhile, then rewire the motor's "high" circuit by using a new relay and power wire, and a new "ground".

By now you've got the picture.

If you want to try to increase the blower's speed at the intermediate settings (those other than "high"), it's more of a trick because of the resistor pack that's in the circuit. Let's worry about that later.

 

[HotWheelsBurban]

do the small vents on the floor help at all my former friends extended cab has them and I think our 3500 has them as well or do they only work with the heater and I agree with the post you have made a few times saying that the crew cab should have got the roof vents like the suburban or at the very least it should have been a option

There is airflow out of the floor vents if the switch is set to that position. Better for heat than AC though. And the one on the driver's side has a toolbox in front of it, but there's only ever one person in the back seat.

 

[1998_K1500_Sub]

You might also try to improve the AC performance by installing an adjustable cycling switch. @L31MaxExpress talks about it here:

https://www.gmt400.com/threads/ac-pressure-switch-keeps-failing.68097/post-1422852

In a desert environment, freezing the evaporator is not a concern.

 

[L31MaxExpress]

You might also try to improve the AC performance by installing an adjustable cycling switch. @L31MaxExpress talks about it here:

https://www.gmt400.com/threads/ac-pressure-switch-keeps-failing.68097/post-1422852

In a desert environment, freezing the evaporator is not a concern.

I am actually about to add a toggle switch that bypasses the cycling switch for the very low humidity, insanely hot days we have where I live in Texas.

 

[1998_K1500_Sub]

I am actually about to add a toggle switch that bypasses the cycling switch for the very low humidity, insanely hot days we have where I live in Texas.

Have you ever seen a compressor lubrication shortfall in this situation?

I'm thinking...

- the compressor's running all the time,

- the refrigerant flow may at times be low (on account of very low humidity, low blower setting, ambient temps, or other)

- consequently not much oil is circulating to the compressor, even though it's constantly engaged

It's a random thought I've had, and I might be overlooking something.

IIRC, the old A6 compressors could be run all the time but they had their own oil sump.

 

[Vettepilot]

Well, I would dearly love to know how to make it blow harder. There's almost assuredly a motor out there that would be better, if we only knew what it was. Being a "squirrel cage" type fan, you can't change that.

Surely we are not the first/only people to want more air out of these...

Vettepilot

 

[GoToGuy]

Do a search for squirrel fans with deeper blades , will move more cfm at same rpm.
12 volt fan motors can be found in various rpm .