I have a Kenwood KDC-BT858U with a Roker 500w 4 channel amp. The system was working fine. While riding the other day I was listening to a song and it all of a sudden the volume dropped off to nothing. No sound out of any speaker. At first I thought it may have been a problem with the blue tooth. When I got home I noticed the volume bar would go up and down and the song was showing on the screen and I could even go to another song using my handlebar controls. Then I turned the radio to tuner. Still no sound at all, not even static. Everything seems to function correctly on the head unit. The main fuse to the amp is good. I pulled the fairing and both fuses on the amp are good and so is the fuse on the back of the stereo. The power light on the amp is on. I checked the connection on the RCA plugs. The only thing I noticed that didn't look right was the fan on the amp wasn't turning. I gave it a little nudge and it started turning but not up to the speed I would think it should. Any ideas?

 

try to eliminate component by component.
for example:
I would disconnect the RCA's from the amp (assuming you run pre-outs to the amp) and then measure AC with DDM on one of the speaker outputs of the radio while playing a 50 hz tone with the volume up (50% or more). if you got some ac voltage the radio is good.
or if you got a old speaker laying around, hook it up to the radio and play a song.
if sound (or ac voltage) then you know the radio is okay (at least the speaker outputs work; it would be "safe" to say the rca's will work to).
you most likely are looking at a "dead" amp then.
also check if your remote wire to amp is connected correct.

 

Yeah, I thought about finding a speaker and connecting to the radio and I guess I still can. What deterred me from that was the wire plug harness is all taped up and goes to the Biketronics module. It will be a PITA as it is all secured but I guess I will have to do it.

You lost me about the 50hz part. Shouldn't I have some AC voltage with a song playing?

 

it will be hard to see, but you should... it will most likely bounce all around.
if you use a pure sine wave ("any" single frequency wil work), your ddm will be easier to detect the AC voltage. as songs are a complex combo of all kind of frequencies...

 

Thanks, I will check it when I get home. I put the fairing back on so I could ride to the bar. I hate pulling the fairing. Mine is tough to get back on by myself. I usually just start every screw so I will have some play but the bottom ones are a bitch!

 

if you lost all sound through all speakers at the same time, I would suspect the amp even moreso with the fact that you pointed out the fan wasn't turning on its on and is turning slowly. might be time for a call to J&M to see what John says.

 

I was on the highway and running pretty hard. The sound may have cut out and came back for a second or two but then all speakers went silent.

Thanks guys, I struggle when it comes to this audio stuff.

 

I would go back and check your power and ground wires to make sure they're solid and intact.