have a 69 b body with the factory AM radio and single rear speaker. when I bought the car the radio did not work meaning when you turned the radio power on you did not hear anything. car is now a part and i would like to trouble shoot this. What is the simplest way to test whether my radio, wiring, or the speaker itself is the culprit on the benchtop? have no spare radios or speakers lying around, but only my AM radio and the single rear speaker.

W the battery and radio on your bench and some jumper wires, positive to 12V input and make sure you not on the dash light but the actual power in, ground chassis to neg. 2 wires to speaker. I think there is a little "trimmer" knob somewhere on the case to fine tune the reception but it sounds like your dead in the water. Not sure if there is an internal fuse or not. Not much info but that'd be where I'd start and almost forgot if you get any noise you'd want to plug in the antennae and jumper it to the case also

You can hook the black and green wires directly to the speaker and see if it makes sound for ya. You will have to ground radio. Assuming it has a fader also, you can eliminate problem as you get further away from radio.

I'd try to find a friendly Ham radio operator or advance CB guy in the area and ask him do a quick check for you. Most radio install shops wouldn't do that service for free but you might find one, they of course want to sell you a new radio.

All the of the above is good advice. If you do not have an antenna attached, you may not hear anything still. Take the covers off the radio and hook it up. On the antenna connector on the inside, put your finger on a screwdriver blade and touch the antenna input, not the ground. You should hear signals from strong stations with your body acting as the antenna (yes, you can do this at home even as an untrained non professional). If you do hear stuff, the radio is working. If you don't next step is to find the volume control. Using the same technique, put the screwdriver on the middle lug of the volume control. You should hear hum in the radio speaker variable with the volume control. If there is not, the audio section of the radio is bad, probably the output transistor. That is the most probable failure of a solid state car radio.
With tube type radios, don't do any of this because you could get knocked on your can.
One other tip, the volume control is usually concentric with the tone control. The volume control is the rear gang of the two controls.
Craig

Maybe rephrase it: Not enough noise will be present to detect in the speaker, especially with these old ears.

Generally , with an AM , with no antenna plugged in you will hear nothing at all, and with an AM FM, only the strongest stations will be
audible with no antenna .
You mention only having a single rear speaker in the car . All '69 B bodies with R11 came with the single 4x10 dash speaker. A single rear was an option , and would pass through a factory rear fader switch.
If you can't get it going , that's what we do all day ,every day , so send me an e-mail.

Greg