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Bench testing a radio, need to identify which wires are pos/beg.

Started by 72 Challenger, November 30, 2017, 05:06:16 PM

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72 Challenger

Hi folks,

Looking to verify if a radio I have on hand is in working order or just a good looking dud.

Am only Motorola unit 2884759. My tag on it says it came from a 74 cuda, it's going into a 72 chally.

From the picture below which wires are pos/neg. both for the larger connector that goes to the radio and the smaller connector and loose wire that goes to the speaker.

I assume for speaker wires Black is negative?

Looking to bench test it with a car battery.
Someday I will have a J0b.

Chryco Psycho

Red is 12v +
Orange is dash lighting
Green is speaker +
Black is speaker neg
ground is through chassis

750-h2

To test with a battery would you place the negative battery wire on the radios metal casing or is there designated location to ground it?   Thanks!


Chryco Psycho

The steel body of the radio is ground so you could set the radio on the negative post or use a jumper to the steel case of the radio to the battery negative post .

fc7cuda

Quote from: Chryco Psycho on November 30, 2017, 09:12:22 PM
The steel body of the radio is ground so you could set the radio on the negative post or use a jumper to the steel case of the radio to the battery negative post .

:iagree: I usually run a jumper wire from the neg. battery over to the rear mount stud.

Good luck and hope the radio works.  :fingerscrossed:

72 Challenger

Someone else asked my follow up question!

Will I hurt it if I run battery power to test if the light works?

Thanks guys!
Someday I will have a J0b.

Chryco Psycho



72 Challenger

Thanks for the help guys, she works! Both light and radio. Just need to hook the antenna up.
Someday I will have a J0b.

Chryco Psycho

Great , now if only there was something decent to listen to on AM

72 Challenger

My guess is that it will remain off the majority of the time.

I rather listen to my engine than the knuckleheads on news/sports talk radio.
Someday I will have a J0b.