Okay, now we can get serious! Having a meter but unsure of how to use it is pretty common, so no harm in giving a few tips. Many have them but don't have trouble often enough to really get down how to use them.
First big point is that we DO NOT want to mess things up! Step one is to know that we do not want the probes to touch two points together to short them out as that can cause harm --or sparks! Second is to be sure that the meter is set to the correct range or setting for what we are doing.
Basic safety for the meter is to have it on "V" or voltage setting when we are unsure if voltage is there or not. Setting of DCV or ACV is not so critical as neither should burn out the meter but when we want to get a reading we will need to go to AC or DC as needed. For batteries, use DC. The problem with the setting is that some meter will burn out or blow a fuse if we stick it on a voltage while it is on the resistance/ ohms or the funny "squiggle" setting.
Think of voltage as how much it wants to get from A to Z, and ohms or resistance is how much things are try to keep it from getting there? Dirty or loose connections are a major cause of high resistance and a wire that comes off is infinite resistance.
So for what we need to find here, we can stick either probe on the battery terminals and it will tell us how much charge the battery has. We could get techie and debate which probe goes where but not needed as all we want is the level and it is not often going to be backwards, so I keep it simple and ignore which goes where. The number will be plus or minus but we don't care!
So once we know what the battery reads, we need to know that the wiring from there to the monitor is good, so we need to get at the plug mentioned in the trouble shooting. Can't say how that is done but take a look to see if it clips on or is screwed on the wall?
Then when/if you get the plug off the monitor, stick one meter probe in the hole 5 on the plug from the battery or touch it to something like the frame for ground and the other probe to 2 and see the coach battery reads what the monitor says. Gives a boost to the confidence to see you are doing it right?
Then to test the chassis battery level getting to the monitor, move the second probe from 2 to 8 and that should be near the same as the battery reading. A couple tenths lower might be expected due to the resistance of the wires and connections along the way but definitely not 4. 0 Volts!
If the battery reads right on the plug, the next step is to say the monitor is not working right.
But first step for me, would still be to go through the reset AGAin just to be sure I was not walking past something obvious as electronics like computers and phones have a nasty way of being just plain silly about doing what I want!!
AND I don't want to do a bunch of work and worry if a few button pushes might get me clear.
An alternate to fixing/replacing the monitor is this little gadget:
https://www.ebay.com/itm/New-Mini-Ca...366062b609bdb3
Linear Mode
