Can anyone answer this question ?

[mjc85]

I am curious to know if anyone knows how much power the air conditioning draws off the engine ? Also how much would the alternator draw off the engine ?

Thanks
Mitch

[kylebes1]

with the m10, high mileage hp estimate was like 85, would be luck to get up Georgia hills in fourth, so I would say the old a/c killed a good 20 hp.

Not sure if the alternator would take away much.

[EverWiser]

The alternator probably takes 1 to 2 HP and the A/C compressor would take less than that when "OFF" (clutch not engaged) because the pulley is free-wheeling. With the A/C "ON", depending on year of compressor, probably between 2 to 5 HP. I'm basing this on the fact that most newer compressors are a lot better in efficiency than compressors from the '70's. Even if it's an older compressor I can't seeing it use more than 10 HP...