Radiomobile 1085X

[Fuel.inj]

I’ve acquired this Radiomobile 1085X which appears to be in very nice condition but before testing it I am unsure of the wiring especially the green and purple wires. It is a negative earth unit but the question is which is the earth and which is the positive as I don’t want to damage the system. Any help will be appreciated.

[Heuer]

Green is usually power in cars. Put a ohm meter on the case and on each wire, the one with zero ohms will be the earth. The case is earthed on all car radios.

[caveman]

From that famous online auction site, here’s a 1085x with fused purple (power). There’s a brand NOS on there also displaying same. These units use the outer casing to earth. The green wire may well be retrofit and wired for aerial electric feed (12v when radio switched on). Easy to test once you get the set powered.

[caveman]

Here’s another:

No green on any

[Fuel.inj]

Thank you all for your prompt responses, really helpful as always.
Regards, Paul.