I had to replace my starting battery because of a bad cell and thought I would check what the amp draw was with the ignition off just in case I had a parasitic draw. Turns out I have a draw of about .9 amps. I have no idea if this is normal for an old motor but I suspect it is not. I would think anything over .05 amps would be suspect. Where should I start looking?

I found my primary draw was a hard wired CO detector. My solution was to add a battery disconnect to the negative terminal.

The alternator may have a bad diode... remove the wires and see if the load goes away.

Great suggestion. Last night I checked the alternator by starting up the coach and looking at the waveform on my scope. I had less than .005 volts AC on my scope. Then I removed the wires from the alternator ( I never trust meters unless I have to ) and the load was still there. This after noon I guess I will start pulling fuses and see If I can isolate that way. I seen a chart online where you can measure the voltage drop across a fuse if there is a load on that circuit but the drop would be in millivolt range and I don't think my meter is that accurate.

Definitely start pulling fuses, one at a time. Some of the circuits (like ignition?) may be fed by fusible links in the harness. Good luck.

Ole Nose has a off draw of 9 milliamps, I stuck in a disconnect to the dash and left the starter cable connected, no draw at all now. Not sure what that 9 MA is but the cut off works fine. If I forget to close the disconnect Nose still starts but without any dash stuff.

older thread but maybe some info of use..

Battery Drain..

My aftermarket radio works with the key off, but not with the battery switch off, so I know it's drawing off the starter battery. Even when off, I'm sure there is a slight draw. I always turn the switch off when parked.

If you have audio and video equipment and “smart” appliances there will always be a small drain of power. This is to keep memory components alive. If you disconnect entirely you will have to reprogram every time you energize your system. Better to install a Battery Tender to preserve the batteries. But it should still be no more than 250 - 300mw draw.