Radio, Clock an errant "wall wart" (charger somewhere). Many devices can be OFF yet still pull a trickle.
If the obvious aren't the culprit then more drastic diagnostics.
The fridge will still draw a little power for temp sensing, it should be quite low BUT I know that they can fail too, test by disconnecting the 12V from it and see if the draw vanishes... Some on-board water heaters (even with LPG) can have temp or pressure change sensors to start heating, depending on the type of water heater. Check the specs for the Make & Model of your fridge, water heater to see IF they have any live sensors and what the idle draw should be if they have them.
If vehicle 12V Starter battery & electrical are 100% isolated from the RV power side then it get's a bit easier.
If the RV side has a fuse panel, then pulling each fuse, one at a time can help determine which circuit is drawing power.
Chasing down the circuit with a draw is the start, if more than one device on that circuit, then to test the device.
IF the two 12V systems are interconnected, even with isolation there could be an issue. It means pulling fuses from the block as a start. Warning if you have an Auto-start system or security system, be cautious ! and checking to see if the draw is eliminated.
If you disconnect your "house" battery, is anything that should be ON go off ?
Also, if you disconnect vehicle battery, is everything that should be ON still ON from the House Bank ?
Are any of the vehicle circuits (like the radio for example) still ON if the Vehicle battery is disconnected ?
If either happens, there could be a cross wiring or short. Some intermittent shorts can drain power. Some equipment which requires proper grounding that is failing can also create many errant issues (usually the vehicle computer will act up if vehicle system related for example) and boy that can make mechanics heaps of cash.
Electrical Gremlins are MISERABLE and even moreso when it involves vehicle systems and worse when there are dual systems with connections... More complicated the more issue potentials one faces.
Hopefully some of this is helpful
Steve
Thanks Steve,
The starter battery has a disconnect leaf switch that isolates it entirely from the rest of the setup, so I can start with that disconnect, and check the fridge power for ambient draw. (mechanic stated that 0.02amp draw was acceptable normally, but this was 0.2, so outside of acceptable bounds).
The rig is older, with no alarm installed, and the radio turns off when the engine turns off.
The stove light & fan, roof vent fan, and all of the interior lighting is hooked up to the House battery, but they are all off, and switched over to LEDs for power saving.
I think the fridge and water heaters are the best bets, but the water heater isn't used much (and not at all while working through the parasitic draw), and the fridge was looked at by the same RV tech who discovered the issue, and he didn't find any link when briefly investigating.
There are two starter battery isolator relays under the hood, but they were not set up correctly. I started another thread asking about a 3-way DC-DC charger that could solve this, and possibly lay groundwork for a solar setup, but I wanted to square the unknown power drain first.
This Gremlin has vexed 1 RV tech, and 3 mechanics so far, though to be fair, the mechanics were apparently baffled by what I was talking about so.. *shrug*, not a lot of faith there in their abilities.
Thanks again
- Dave
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