E2 heating error on Dual Extrusion

I'm having heating issue as discussed in gCreate's "Heating Failed" post today.
They suggest to check connections
I've checked physical connections, but be sure they are in the correct place. A coworker set up this gMax 1.5 Dual Extrusion a long time ago. He is no longer with company.
I really need to see a wiring diagram / installation manual to check if everything is connected correctly.

I need to know which power wires go for which head? circled in red
Green/White for head?
Red/Black for head?

I need all of the details about the circuit board. circled in green.

On the resources page "Dual Extruder Installation" has no link to info.

Can anyone help?