check the voltage under these 3 conditions each time you check it. key on engine off, at idle and at 3500 rpm, both engine warm and ac off. check the voltage at the white/red wire with a digital volt meter, no analogs. 1.6v, 2.7v and 3.5 volts. this will tell you if the amm is bad.

set the resistance at 380 ohms between 12 and 36. this is the basic setting. then you need to let it warm before doing any adjusting. an asjustment cold or hot affects everything, so if you set it cold and it runs better when warm, you have another problem, also. i'm sure the faq has how to set when running. i have the volvo test diode and use that for adjusting. good luck, chuck.