[71 T/A]

This is for my 72 with a/c.

[2manyT/A'S]

Originally Posted by 71 T/A

This is for my 72 with a/c.

This doesn't really answer your question...but make sure that all your ducks are in a row....or at least in place ...lined up... and and the joints are sealing as well as they can be..

You MAY be loosing velocity there..

[Formulabruce]

Originally Posted by 71 T/A

This is for my 72 with a/c.

The hi speed resistor may not be right in your case under hood. There is a relay there too for high speed.

[rexs73gto]

There has been a lot of talk about a motor thats blow harder & faster on the A-body tech posts. Some have used a late model motor form some other vehicles . I don't remember which ones they were using but you can do a history search to see the posts.

[cuz68]

It was from a dodge truck, I forgot the years.

[teeraven]

I've wondered this too. 70s and 80s car just have weak blowers. I'm sure it's partly air leaks and the age of the blower motors, but they just don't blow like modern cars.

Another thing to check is the voltage drop across the motor. If it's significantly less than battery voltage, you've got a voltage drop somewhere else in the circuit and that would slow the fan down.

I've been planning to look for newer blowers that could be adapted to fit in my 70s stuff, but haven't gotten around to it yet.

[Held for Ransom]

http://www.forums.maxperformanceinc....d.php?t=761982

One answer.

[Formulabruce]

I have looked into this. If you look at an AC car, with A/C off, and check the voltage at idle at the battery its about 13.8 ( internally regulated Alternator). Put a load on it and eventually the Alternator brings it back up over 13. Turn the A/C on HIGH and at Idle ( under 900) the Alternator does NOT usually keep Voltage up at 13.8 even with a 63, or 80 amp unit. While it provides needed current, and charging, the blower motor only runs on what it gets, Mine was at barely 12. The power comes through the resistor block in the case itself ( underhood) but easily accessible, and testable for each speed. I put a small transformer ( ran it as a step up) and ran the blower, on high at 15 volts ( about 2 amps If I recall) . For this to provide the desired effect and stay cool, the Evaporator should be clean . Mine worked great and my system was R12.