55 Roadmaster Electrical Mystery

[Paul Falabella]

Radio stopped working the other day. No power in lead. Traced lead to behind left kick panel(not supposed to be there). It was connected to a box with several other wires going in(have not traced these yet). Inside the box is a 25 micro farad cap and several tiny resistors on a board. Voltage coming out on 1 wire was 11.3. Battery reads 12.3, same as several other circuits.

Radio lead, I believe, is supposed to be connected to the rear bottom lug(with antenna power) of the lamp rheostat combo switch. This would allow the radio to be turned on without the key in the on possition. Is this correct?

And what of this peculiar box. Any ideas?

I hate juryrigged wiring with no roadmap!

[bhambulldog]

I don't know about the box......

Radio originally is wired to play with the switch off.....

Don't crank the engine with the radio playing however....

It can damage the radio.

(i answered this question on your other thread before I saw this thread....)

Edit:

25 micro farad cap and several tiny resistors on a board.

That sounds like post '55 technology...(?)...

My radio has worked flawlessly since we've had the car. So, I've never delved into the wiring of it....

Edited April 10, 2013 by bhambulldog (see edit history)

[Joseph P. Indusi]

The box with the 25 MFD capacitor and the resistors sounds like an aftermarket voltage regulator. Do you see any diodes or transistors in there? Possibly some kind of interference filter.

Good luck.

Joe, BCA 33493

[Paul Falabella]

That makes sense.The voltage output was only 11.3. I wired the radio directly to the light switch and it works fine. With this mystery box it was wired to the ignition and only worked with key in the on position. One problem down.