1989 Cadillac Eldorado Bose No Sound
 

Very little to no sound coming from the speakers in my 1989 Cadillac Eldorado, but the radio has been sent in and verified good. Is there a relay for the speakers that could be causing this?

Most likely the amps which are part of speakers. There are two fuses and relays that power amps.

I would check the amps next more specifically, the remote on wire, ground, power and fuses. use a multi meter or test light. if those all have current you need to check the feeds (the left right front back and center channel supply wires) -- i am assuming you know for sure the speakers are not blown? just one could foul out the entire system causing a short.