Can I back probe (apply currant to this light circuit) to check continuity of wiring. I have checked for blown fuses and replaced headlight switch because radder rheostat was faulty.

thanks for looking

 

I think the switch provides ground path. Start checking for power at the various locations.

 

Thank you for your reply.

It turns out that the fuse marked "IOD" 10 Amp was the culprit. It was covered by a shield so was not readily available for checking. I do not know what caused the over draw but will have to monitor.

 

Might be as simple as age. If the radio forgets everything it knew as well, IOD is the first place to look.