96ram1500

That was a very quick reply. Kudos Moparman. I will try to post my alternator waveforms and see how you read them.

I am relatively new to the forum but have heard of Moparman and used his wiring maps for a while. They are very useful. Very good job. My throttle surging issues are caused by varying voltages to, and subsequently from, the APPS. I have the same issues with the alternator and/or PCM disconnected. The issues are as follows: -Truck starts right up but idles erratically -engine idles fine with ECM data lines disconnected from VP44 (wires removed from connector) -engine idles fine with APPS disconnected (no fluctuations in incoming voltages) -40 HZ (or thereabouts) "signal" in power and ground with and without alternator (oscilloscope screenshots available, Spike at about every 25ms and .5V) This is s perplexing system as I can't tell if the VP44 is injecting this 40Hz signal and causing my ECM to throw a fit or not. The ECM is obviously giving an unstable voltage to the APPS and not liking what it gets in return. I just don't know why it is supplying an unstable voltage when it is supplied a stable 12v. This is very confusing. Can anyone shed some light on this 40 Hz so I can narrow down my search? Maybe its coming from the tach signal from the VP44? I haven't checked to see if it changes with RPM's but I will. As stated, I am relatively new to the site so if this has been covered, feel free to make me look stupid.