Higher power fresh air blower?

[MD540iT]

Im thinking about pulling out the A/C blower since I have no AC... but the fresh air/heater blower is pretty weak, has anyone ever installed a higher power motor?

[jjeffries]

Looking at the Griffiths/Kuehl website may be a good place to start. He’s a great guy, what he doesn’t know about Porsche A/C isn’t worth knowing, etc ... and not just in terms of 911’s.

griffiths.com

Please keep us posted.
John

[v2rocket_aka944]

hook it up to an 18V drill battery, and hang onto your hat, LOL

[djnolan]

Is it needed on a late car or just the early cars?

also I always use recirculate so it doesn't pull as much heat or humidty in.

[Jfrahm]

Originally Posted by MD540iT

Im thinking about pulling out the A/C blower since I have no AC... but the fresh air/heater blower is pretty weak

There is only 1 blower for both heat and AC. If you have a later 968 maybe you have dirty fresh air filters?

On my cars the blower seems fine.

[MD540iT]

this is for a 931 early 944 style

[djnolan]

Does the blower work on all speeds? If not it could be an electrical problem with the switch and blower resistors.

https://www.pelicanparts.com/techarticles/Porsche_944_Turbo/16-ELECT-Blower_Motor_Resistor_Replacement/16-ELECT-Blower_Motor_Resistor_Replacement.htm

There is a good diagram of the whole systems here: 944 HVAC Operation and Malfunctions

[MD540iT]

it works, just weak, unfortunately the A/C blower is much more powerful, but in the 924, the center vents only work with the A/C blower. I don't get why they put in such a weak motor, especially for the heater!

[MD540iT]

hmmmm, why not get rid of the resistor to give it more power?

[Jfrahm]

That would mean fewer speeds. The resistors are for the speeds other than full.

[MD540iT]

but what if I use a potentiometer to control the speed?

[Jfrahm]

So instead of a resistor, you'd use a variable resistor?

You could not fit one that'd take the power and even if you could 0 is still the lowest setting on the pot, so the blower would not speed up.

To speed it up you'd need a boost converter that could handle 30 amps plus to increase voltage to the blower. Beyond what the current system does in full speed (resistors bypassed).

Have you verified yours is working as it's supposed to? Doesn't have a mouse nest or broken fan blades or something?

There are some posts at 924board.org about blower motor issues.

[v2rocket_aka944]

the blower on full speed moves a decent amount of air, but i would almost hesitate to increase its output for heater use.

early 944s have VERY good heaters and you will cook even faster!
i believe the 924/931 use the same blower as the early 944?

[MD540iT]

this is a 924 turbo, its common knowledge the blowers are quite weak

[djnolan]

The vents and ducting are smaller too. Is there a way to get air flowing through all ducts floor/dash/windshield at once to increase overall airfolw into the cabin, especially in summer A/C season? Also use recirculate to reduce heat/humidity injestion.