Originally Posted by bobas
Thanks Too Tall. i will check out other electricals. After i posted, i thought about what my dad tought me many years ago. If you have a minor electrical problem always check the ground connection first. So i pulled the battery to charge it up and found the battery cables are corroded. They are now cleaned and battery is charging. Will check tomorrow to see if the monitor works. I too don't trust the monitors completely, but it does give you an idea of about where your tank levels are.
The switch's are momentary switches so need to be held on to get a reading. As long as your tanks are clean the "idiot" lights do work ok. The one most likely to lie to you is the black water tank. Need to keep it clean!
As for the battery, I wired in a cheap volt meter. I can turn it on or off and get good readings on my voltage. With no heavy load on your battery you should get the following readings. Percent is voltage left. Shouldn't let battery get below 50%
Below 50% you may damage your batteries.