VCCA Home Forums TECHNICAL - 1945 AND NEWER 1971-1979 radio spkr help

bought recently on EBAY a 70-80ish delco am/fm. i read some posts here about the spkr wires. i need more help than those posts. i am testing the radio outside of my 73 GMC truck on a workbench. the radio yellow wire is attached to the positive post of the truck battery coming from the BLK plug top plug. the blk wire is GROUND goes to the body for ground. the lamp wire is attached to the yellow power wire. i test the power wire and lamp wire with a test lite, they both lite when touched. i only need the FRONT spkrs. The spkrs testing with are 4ohm-8ohms. I've attached 1 lt green to the + side the drk grn to - side. i get no sound. the spkr is hanging on a nail to the wooden shelf. do i need 8-10ohm spkrs. also want to attach an amp. thanks in advance for any help. classic73

Those radios used a quad amp and if at anytime was grounded to the chassis fries the amp. Most likely if you have an antenna plugged in and hook up one set of wires + and minus with the the speaker ungrounded then the quad amp is bad if no sound. Come across this all the time. Sometimes if you're lucky one set of the set of 4 speaker wires will work. Hard to get quad amps to replace and costly if you do. I end up converting these to 200 watts 4 channel for less cost and trouble then to replace the amp. Also if you are hearing a thump when turning it on their is a problem in the rf or if circuits as that means the amp is working.

What do you mean by a quad amp.i am a novice at this type of installation. i don't have an amplifier attached. i was told the amplifier helps to get higher sound. i don't get any noise when radio is turned ON. the spkr is ungrounded that i am testing. The radio is on my wooden work bench. i do have the blk grnd going to the body chassis. ? will an amplifier from Autozone work with this radio. do i need 8-10 ohm spkrs. thanks for any help. classic73

The amp I'm referring to "quad amp" is self contained within the radio. for this model. If you are not getting a thump when the radio is turned on it means the amp in the radio is not working. You cannot replace it with an autozone amp. The radio needs to be serviced or repaired or you need to buy a working radio.

Bill