We found the short causing the fuse link to blow and my Z is running again.
While waiting for an auto electrics expert to help me, I discovered melted connectors on the defrost switch. The switch was left on by mistake causing the short issue.
The switch was non-OEM, with a built-in light and a PO cut the console plate to install the switch. The switch light was burned out, so it was easy to miss that it was on.
My expert arrived at this point and he set-up a 12v light bulb to help identify the short. He also added a 25 amp push button fuse to protect the circuit during testing.
The bulb lit when connected to the circuit, so he knew there was a short. (I do not know how he connected the test light, since I was in the driver’s seat).
He suggested that we remove the Accessory Relay, since it is part of the defrost switch circuit with a potential problem. With the Acc Relay removed, the light went out, so the short was identified somewhere in the Acc Relay circuit.
I traced the three defrost switch wires: 1-Ground to cigarette lighter body screw, 2-to a female connector and 3-to a female connector with an inline fuse.
The inline fuse contained a 25 amp fuse with a small burn hole. The inside of the holder was brown, plus part of the wire was melted and exposed.
I cleaned the holder and copper connection inside, plus I put shrink wrap on the burned/melted wire and inserted the proper 20 amp glass fuse.
See attached photos for before/after repairs.
Before connecting everything back up I tested the accessory relay circuit. With the relay still detached, I used jumper wires to connect three of four pins. Between the blue-red wire, I attached a 12v bulb. I turned the key slowly from lock to start. The relay clicked correctly at ACC and the bulb did not light as I started the car.
Success! No light = short fixed. If the bulb burned bright, we would have still had a short.
With positive test. I removed the temporary push button fuse and installed the correct fuse link.
The Z starts and runs fine again.
Appreciate everyone’s assistance with getting my Z operational again.
(My Z now blows the brake light fuse when the turn signals or hazard lights are used. Will do a separate write-up to discuss.)
Nate