[GoGoat]

On my 66 A/M radio. Looking at Back plug has a yellow hot wire on right, center green wire to speaker, left wire to ground. Is this correct. Had smoke coming out of radio. Have 2nd radio but want to confirm wiring. Would defective speaker cause radio to smoke? Not sure if speaker is good.

[GoGoat]

Also was the radio grounded thru grd strap on bottom or thru the knobs? And third left terminal on 3 connector block the grd for the speaker?

[Scott Thelander]

radio plug from a 68
fairly sure the earlier cars were this way also
69 changed

[Scott Thelander]

radio is self grounded if its mounted in the car

bench testing it will need a ground

[GoGoat]

Success , First radio and speaker works now. Thanks for help

[Peter Serio]

On those old 1960s radios; ALWAYS remember you need a 10 ohms resistance speaker. If you ever test one of those and run it wired to a modern 4 ohm speaker you will fry the amplifier transistor in about 3 or 4 minutes. It overheats.

Most modern (new) car speakers are NOT 10 ohms, they are either 4 or 8. The older GM car radios are based around a 10 ohm speaker.