2003 Dodge 2500 Van.I have the usual bad pcm internal voltage regulator. I do have external wired in and it is charging. The problem I am having is that the white/ blue wire that was on the alternator plug supplies 12v to the trans relay. So without this transmission goes into limp mode. I have tried to hook it up several ways with n luck. Also I noticed that when the system voltage is low the van will not stay running without foot on pedal. Looking at the wiring diagram the red wire coming off the trans relay goes to the plug on the transmission. I have power there but it’s very faint on the test light. I have been looking for others that have had this happen since the external reg is pretty common. I have replaced pcm twice already and the regulator has went out and transmission has shifting issues each time. The crank position sensor, pick up coil, cap, rotor, all transmission solenoids, have been replaced. New battery and alternator. Any help would be fabulous.