I just redid the A/C on an 87 turbo buick. New comprssor, accumulator, orifice tube. It works well and is cold but I can really feel it engage and disengage like it puts a good load on the car. When it disengages its like it gets more power and a load is taken off. Is this normal? It's been so long since I've driven one of these where the a/c works so I don't know what's right and what isn't.