1998 Roadtrek 190 Rear speakers, no sound

[John Ross]

I have no sound from my rear speakers, balance control works, but no rear sound.
The wiring appears to go inside the walls.
Is there a fuse, or amplifier for the rear speakers?
I had the radio out and put contact cleaner on the balance control, got rid of scratchiness, but still no sound on rear speakers.
Any suggestions are greatly appreciated.

[GallenH]

John, if you have the manual or can look up the specs on the radio you should be able to see if the rear speaker feeds are powered by the radio itself or are just coming out at pre-amp levels. If they are pre-amp, that would indicate that there has to be an additional amplifier somewhere. But if they are not, it probably indicates some fault in the wiring. If the radio is newer than the original, it's possible that there's an incorrect connection at the radio itself (for example, some newer radios can power all 4 speakers but also have outputs for all 4 that are pre-amp level in case the user wants to use their own amplifiers. Possible that the installer connected the rears to the pre-amp outs by mistake.) You could have a wiring issue to the rear speakers but I would doubt that both speakers could have a bad connection or a short.

[John Ross]

Thank you Gallen.
I have the service Manual for the 1997 Ram 3500, which the chassis is for my Roadtrek.
It doesn't show me much info, and I was wondering if Roadtrek would have modified it somehow and added an amplifier, which I can't find.
The speakers that work are in the front doors and can be made to vary with the balance control on the radio.
If there is no extra unit or fuse, then I will have to remove the radio again and fault find from there.
I have not been able to find a schematic for the radio on line.

[John Ross]

hI all,
I removed the front drivers seat, and found what I thought was an amplifier, it wasn't it was for the airbags.
Anyway, while there I tidied up the wires and checked harness connectors for tightness.
Put everything back together.
Then I proceeded to remove the dash to get at the radio again, to check the output at the radio. Previously I had tried to get a signal tracer, but was unable to find one, even at The Source, the old Radio Shack. They didn't have one but they could order one, maybe.
I then remembered I had an oscilloscope from my old days of repairing electronic organs, so i was going to use that to signal trace.
I turned on the radio while taking the dash apart, lo and behold the rear speakers were working, so it was abad connection under the drivers seat.
Thank you Gallen, I find that in my older years my mind does not work as well as it did. You got me thinking in a logical way.
Best,
JohnR