[ET160]

My car drive poorly with the A/C on. When the compressor kicks in the engine takes a hit. Is this normal, or is there something wrong with my car?

 

[FC Saab]

Probably an issue with your compressor if its causing that much drag.

Is it when the high speed fan kicks on? With a bad low speed fan resistor, with ac on and the high speed clicks on it could almost stall my old 9-3.

Check that your fan kicks on when you turn on the AC.

 

[CarpeCyprinidae]

That's a possible.

My Saab 2.3 is a motronic type (no DIC, distributor & ignition coil type) and as such only has a single fan speed (wannabe helicopter mode)

Can confirm that the fan kick in when AC is on causes the engine to briefly stutter by depriving the spark circuit of power, that may be what OP is describing

 

[Mimmi]

My car drive poorly with the A/C on. When the compressor kicks in the engine takes a hit. Is this normal, or is there something wrong with my car?

Your car have 130 hp and AC takes about 15 hp.
Yes, you can feel it.

 

[CarpeCyprinidae]

The ideal mod would be to route the signal from the A/C on switch via the cruise control accelerator pedal switch somehow.......

So that A/C only kicks in when you are decelerating and wouldnt miss the power