CB Amp wiring question on W 900 2010

If you had no problem with audio hiss then the amp being grounded at the battery is fine .
Ground problem occur with audio when they are on different locations with a drastically different ground potential .

Hunt down that amperage issue and let everyone know...Im curious .

 

So I re-read your OP a couple times. You say the ammeter is showing a discharge, but do the batteries actually discharge (like overnight) if the new wires are left in place vs not?

There is nothing about power leads directly to the battery that would cause the dash meter to deflect, unless there is a load on the power leads.

The only thing I can think of is maybe you shook or poked something loose where the ammeter is mounted in the panel when threading the wire through the dash?

I mention this having just run 8 ga wire on my '07 T-600 from the batteries to the overhead. I chased the wire up the outside harnesses to the firewall up high on the driver's side to hit an unused grommet. On the inside, I had to pull the left gauge cluster out to fish the wire then push it up the a-pillar into the overhead. That said, mine doesn't have an ammeter. Only a voltmeter, but it is in that left cluster (next to water and oil temp and pressure). Could be real easy to knock something loose in there.

So here's some possibilities. If the problem goes away when you disconnect your new wires at the battery, your new wire may have chafed on a sharp edge or gotten pinched somewhere. Just not bad enough to make a dead short and blow the fuse. If the gauge is still showing discharge, lay the cluster out and wiggle test it. Re-trace your steps and look for any loose wires or anything out of place.

There may also have been other small wires hooked on the batteries that could have been accidentally left off or pulled off when working in there. I did this myself on an '04 FL Century. Knocked off a miscellaneous small wire with a corroded ring connector while using jumper cables to jump start my reefer. Got done and the dome light in the cab was acting like a strobe, along with the accessory circuits (radio, cig lighter sockets, etc). Reconnected the little wire and all went back to normal.

Last thing without getting too deep is to make sure the ammeter isn't just coincidentally bad or got damaged in the process. So check for current at the batteries with everything off. That in itself could be time consuming with all the crap that is in a truck and how your battery cables are set up. Start with an inductive gauge. You can lay it along a cable for a reading without disconnecting anything. If there is an actual load drawing enough current to deflect the dash gauge, an inductive ammeter ought to pick it up.

Not what you want to hear, but the most reliable way you find a fault is remove parts of the circuit until the mystery load (or gauge indication) goes away. Process of elimination. The crazy thing is that it would be easier to find if it were a dead short and would blow the fuse. Put a 10A circuit breaker in the fuse socket and the shorted circuit will cycle like a turn signal. Use an inductive ammeter and follow it. When you pass the short, the gauge stops moving.