low voltage

[deanjeep]

2011 MADP. I've had issues with my 12 volt power port in the dash. I checked the voltage and its only 8.23 volts. Anything I plug into it just won't work. I found a loose yellow wire behind the dash and it only checks out at 8.3 volts as well. I found the power lead where Newmar pre wired for a CB radio and checked it and it registered just over 13 V. I tapped into that lead and plugged it into the back of my 12 V power port and now it works just fine. Why would any if these wires only be carrying around 8 V? Something shorting out somewhere? The 12V power port is the only thing I've had any issues with. All other 12v powered items seen to work fine.
Dean

[Skip426]

Difference in volts would be , items powered from coach batteries vs items powered from chassis batteries. Are both banks of batteries fully charged ? If your batteries are all up then you have a poor / loose connection in the supply circuit to the dash, either at the fuse panel or further back towards the batteries.
Looks like you have a hunt on your hands.

["007"]

You have to consider the grounds also with your low voltage.
The good 12v pair for CB radio try that ground with the battery lead and see if the 8v's jumps to 12v with that CB battery ground pair of wires.
You could have a high resistance ground connection in a wire nut or twisty.

[deanjeep]

No its not the ground. Even with the original ground I'm still at 13+V with the different power source. I think I'll call Newmar Monday and see what they think. At this point I've only found the low voltage in the two wires. The one that ran to the power port and one that is unused.

[Stan.Birch]

For the purpose of maintaining accuracy, instruments in the dash are typically powered through a voltage regulator which drops the voltage to a level that will be constant regardless of battery and alternator output.