I am having an interesting problem with my AC and engine idle speed. Everytime I have he AC on and running, and then come to a stop sign (ie., put the brakes on) the engine idle speed cycles up and down hi>low>hi>low at about 1Hz (1 cycle per sec). At first I thought this was due to a vaccuum leak, but y/d we located it to be an electrical problem - if you take the fuse out of the brake lights, it now longer cycles the idle speeds, it stays at the high idle just like it is supposed to. So, somehow the brake light electrical system is messing with the engine idle speed, and ONLY when the AC is ON.
I have had the AC recharged, with same problems, and I have had to replace the alternator (for different reasons) with the same results.
Anyone have any ideas on what this might be due to?
Thanks!