Polk Momo rear speakers not working. 2007 Sea Ray 250

[DougHarris]

Front speakers sound great always but Left rear speaker is low and sounds bad. Right rear no sound at all. If I switch front and rear speaker output on amp, Same thing but Right Rear now sounds low bad and Left has no sound. Oh woofer not working either. Saw thread about LPF but I have Clarion CMD5. Don't think there is an LPF function. Please help. Thank you guys!

 

[paulswagelock]

When I had my 270 with the Polk option, I had to adjust the front to read fader on the stereo to make the rear speaker and woofer come to life. Was that way from the factory. IIRC the fader on the stereo had to be mostly biased to front.

 

[DougHarris]

I tried the fader. It works fine with front speakers but when dialed to the rear I get one left speaker working but sounds blown. If I switch the front and rear wiring at the amp the right rear sounds blown. I did at one point have all working fine but just for a minute. I looked through the wiring harness and found a multipin plug about 2 feet from the amp and all was fine. The harness disappears throughout the hull.
Wish I had a wiring diagram. I'll keep plugging along but thank you for the response.