I had an intermittent battery drain on a 4106 that was hard to track down. I though I share this in case anyone else is having a similar problem.
In my case a flaky baggage light switch on my was the cause. But its was not a nice simple failure.
To find it I hooked up a big power supply and monitored the current meter. Initially it looked good, zero current draw as it should be. But sure enough, about a week later a 2amp draw appears. Weird cause everything is still off and no one has even been in the bus.
To make a long story short terminal 44 on the drivers electrical compartment panel which feeds all the baggage lights was the drain. And root cause was a baggage compartment switch.
The switch was failing in such a way it was just barely turning off. Occasionally it would change its little mind and the lights would come on. But of course how would you know since the doors are closed. Once I realized the drain was the baggage lights it was easy to find the really hot ones that had been running for who knows how long and inspect the switches.
Sure is nice to have such great wiring diagrams for these old buses.
Now I need a source for the old style switches with round holes for bullet terminals.
Tom P.
Check Cole Hersee for switches. They have many items for sale that are decades old in the market. On our 4104, we changed to sturdy toggle switches for each baggage compartment. Although you have to REMEMBER to turn them off. You could install a master cutoff switch by the driver to shut them all off with either type.
http://www.colehersee.com/ (http://www.colehersee.com/)
Good Idea on the master baggage light switch considering there are five of these old plunger switches. If I find a good substitute switch for the baggage switch Ill post it here.