Indigoblue

Can someone tell me how to bench test a 1978 AM/FM 8 track radio ( use to know/but forgot) three wiring harnesses in back if I am correct some of the wires are:

Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green

Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue

But what about power, ground , and antenna...??
Thanks
Brian

bmotojoe

That looks correct for a 4 speaker system

Do you have the factory power and speaker connectors?

LINK:https://www.lectriclimited.com/connector-radio-106099

REELAV8R

Power should be fused and heavier gauge, should be relatively easy to identify. Antenna is a female plug for coaxial type insert, ground should have continuity to the case.

at least that’s where I would start. Should be able figure it out with a multimeter to help.

alternatively see which wire supply from the car shows 12v when the key is turned on to identify power.

L-46man

It only plays ELVIS!

Additionally, those units were pretty bulletproof. HOWEVER, if anything was going to die due to time, it would be the rubber (band) drive belt and the rubber capstan.

Amazingly, searches on the net will get you to companies that make replacements!

I had an old Technics turntable....dang! they had the belt!

Good luck.... "the walrus is dead"

Unkahal

Fly skids up!

This diagram is for a aftermarket replacement plug for the Delco radios. The colors may not be correct but the pin location are correct. If I recall the power antenna is yellow also.

BTW do you have any working 8 track cartridges? Lol

REELAV8R

The belt is nothing more than an O-ring. I just found the correct size o-ring and replaced mine 10 years ago, still works

interpon

Here is my 79
https://www.corvetteforum.com/forums...ck-repair.html

KapsSA

Power is yellow.
Antenna is also yellow, one gauge smaller than other but impossible to tell by my eye!(pink on 81-82) Either yellow will power up the radio for testing but must be wired correct to get antenna working. Seems yellow goes in and comes right back out for antenna. (If you connect the antenna yellow to operate radio then power will always be applied to the radio through the orange antenna power wire. Yellow is the trigger)
Black is ground.
Grey is dial light(not sure if there is even a light on the flip door, tho.