2000 ram 2500 diesel 4x4 110,000 miles. when a/c clutch engages there is the normal rpm drop. then it surges approx. 100- 150 prm. the code po123 pops up. when cleared and driven it pops the same code again. the compressor has been changed with no change with problem. it only happens when the a/c clutch engages. code 0123 is the tps/switch A circuit high input.
could the tps have any thing to do with this? with the a/c swith off it runs for miles and miles with no problem. ps i hope i posted in the correct section this time. was really confused the first time posting.

 

Probably. Check TPS with a meter and check connections. Disconnect battery ground first.