I have a 2001 Dodge Cummins 2500. When I Turn on the lights, the engine dies. It's showing codes 1693,1694, and 1689. The scanner said, No comm. between ECM and IPM. ECM detected it could not communicate with injection pump module #1 failed injection pump module #2 open or shorted circuit condition

The first thing I would do is check the alternator for output. It should be about 13.5 volts at idle. Then have someone turn on the headlights and see what the reading is. It should drop some momentarily but should go back up to your original reading. Use a separate ammeter, not the one on the dash to get an accurate reading. I would suspect there is a problem in your alternator, likely a burnt diode, or wearing out, but it may also be the belt is loose, not enough tension. Insufficient power from your charging system could give the codes you are seeing. Uf there isn't sufficient power for the truck to run with the lights on then the ECM and IPM would not be able to communicate.