Many of us have propane level indicators inside the RV that are pretty crappy. Looking at the gauge on the tank (for a fixed tank) is often the only way to get a good read on how much you have left. On my RV that tank is inboard of the chassis rails which makes that problematic. This caused me to do some research.
What I discovered is the LP gauge sending unit is 90 ohms. As I understand it, it reads 90 ohms at the 80% level of an LP tank (which is full). Well, many auto gas gauges are 90 ohm gauges too.
Today, as a science project I hooked up a VDO 90 ohm gas gauge ($10 on ebay) and it seems to work. I have int installed so I can use it while RVing and am going to go through a full LP tank empty-fill cycle to verify it's good. I'll then install it permanently with a switch that selects between the OE system and the VDO gauge. What is nice is when it is "full" at 80% it should read full on the gauge as opposed to the OE system. The OE system is in 1/4 tank increments based on 100% tank fill (which shouldn't happen) so when the tank is as full as it should be it's a tick over 3/4.
2011 Itasca Navion 24J
2000 Chev Tracker Toad
