2000 diesel... when a/c is turned on the rpm drops 50 rpm. then has a sharp 150 rpm rise .when this happens it feels like a sudden surge. and i get the po123 code., but it only happens everytime the a/c compressor clutch ingages. po123 is tps/switch a circuit high input. just wondering if my tps could really do something like that. hope some of you dodge diesel boys can help. thanks ........ tom from oregon

 

For future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html

 

ever have any dead pedal or anything? and do you have any kind of programmer on it?

 

no never any dead pedal and never any programer. really strange problem huh!!!!!!!!

 

check the power cable going to the compressor, they are known to run up against the engine or frame and ground out when the compressor engages causing the symptoms you described.