Just realized, you may be asking where else the blue wires go. The go
between the secondary of the transformer, and the device in question.
Sorry.

No problem. If they are attached to the secondary then the device is a
dual diode with a common cathode. Here is a simple circuit.

http://www.electronic-circuits-diagr...psimages/7.gif




Okay, so I could probably replace them with two stud-mount (is that right?)
diodes, with the cathodes bolted to the heat-sink? Does that sound right?

Dave