Hi Karl,

Looks like you have the wiring on the ICM-1900 side correct. Confirm this by issuing a SHX command and see if the LED on the Crydom comes on. If the logic is inverted, then exchange the 7407 chip for a 7406 to invert the logic. Normally these chips are shipped with the the ICM-1900 so you should have some kicking around.

On the DYN4 side it's a little more complicated.

If you are using the internal 14V supply, you need to connect pin 4 to pin 17. Your connections to the Crydom are correct