Intermittent Stock Radio

[RainjerBill]

Thanks for the prompt reply. In the end, after poking round further, I discovered the JVC unit (from Crutchfield) has a pin-type reset button behind the removeable faceplate. One push and presto! Everything works as intended. I'm going to place an in-line multimetre/voltmetre to the power supply to check for voltage spikes while in operation.

My success here with the JVC unit doesn't explain why the factory unit stopped working last November, but since I'm hip to what it might be, I'll give it a once over on the bench to see if that fuse mentioned was the culprit. I just figured it was a bad unit after 24 years in the Pacific NorthWet.

The Ranger Station rocks!

 

[RonD]

Welcome to TRS

Yes, radios with clocks and electronic pre-sets have a full time 12v wire, but this has nothing to do with radio working, being "on" and playing music

There is a separate "Key On" 12v wire

1998 Radio wiring diagram here: https://www.therangerstation.com/tech_library/pdf_documents/1998_Ranger_Radio_Wiring.pdf

Disregard fuse 28, that is a MUTE radio sound wire used in Ford Radios, it only has 12v when key is in START position
DO NOT hook this wire up to 12v or starter motor will activate

Fuse 29 is the full time 12v to hold radio time/memory

Fuse 20 is the key on 12v which is most likely your issue, for previous radio and the new one, this 12v turns on and powers the radio
The Yellow/Black wire

There are also 3 Ground wires, all 3 need to be tested to make sure each is a good ground
You have tested the light green/purple wire for 12v(full time 12v) do the same test but use each of the Ground wires on that connector to see if you get the same 12v reading on the light green/purple wire

 

[RainjerBill]

Thanks heaps for those welcome details. I will dive deeper.