I just received and bridge wired 4-ch amp to two speakers. Only rt speaker works, no sound from left. Reverse RCA lines from HU to amp, same result. Then reverse speaker output connections from amp, and now left speaker works and no sound from rt speaker. in both cases, speaker driven br rear channels worked and speaker driven be front channels had no sound.

my conclusion is that the front channel amp is bad. Any other ideas? Is it time to return this new amp?

(HU is new Sony ax5000,amp is new Diamond Audio 4v2 bridged to two new Hertz HCX speakers.)

Attached is wiring diagram, unless I effed up.

Have front signals from HU split via RCA into front and rear channels on amp, set in 4-ch mode. So two RCAs to front, for left and rt. And two RCAs to rear, for left and rt.

Got it working, had bad input connector. All good (except now have to find display settings for Sony ax5000 HU).