View Full Version : PMC controlled alternator

08-07-2014, 11:49 PM
I have a 2005 grand marquis that i recently installed a 270 amp mechman alternator onto and i am having some issues. While parked everything is fine but when i put the car into gear reverse/drive it drops to a lower rough idle, than my voltage drops significantly (down into the mid 12's).It even hesitates sometimes when i hit the gas. . Mechman said raising the idle of the car would resolve this issue since it isn't spinning the alternator fast enough to maintain volatage but i would need a tuner. I understand that the voltage output of the alt. is pcm contolled and i would need an external voltage regulator to ever reach higher voltage then what the pcm sets. But the idle is controlled by the pcm as well and EVERY shop i call tell me they are incapable of raising the idle..Would appreciate any suggestions!!!!!

08-08-2014, 01:28 AM
Smaller diameter alternator pulley will make it turn faster if that is in fact the only problem

08-08-2014, 10:23 AM
I'd check the IAC to make sure it's working right first.