I have a 91 740 wagon and I've been having some speaker troubles. I think the radio isn't the stock one that came with it, it's another Volvo model, I will check the model number later on. The problem I've been having is that the left rear speaker doesn't work well, it just barely puts out a sound. I tested it on the right side and it works fine so It's not the actual speaker that doesn't work. It will cut in and out randomly. Would this be a problem with the amp or the actual stereo?

 

It is probably a bad connection. Pull the stereo and check the wires. Then check the amp.

 

I've already pulled the head unit out and unplugged and cleaned connections, how would I go about checking the amp? What do I check for? I don't know much about how the amp is powered or wired.