Vampires and multimeters

Originally posted by GLBCamper I agree that I'm not seeing the mechanical correlation, but I've double checked my amp draw results and continue to get 2.4A on demand and no additional draw on standby. Sooo...?? Remember, the pump was making NO noise in standby mode before. It just sucked amps, overheated and tripped.

Hmmmm.... while that could certainly affect the overall flow, I'm not sure I can see how it would cause the pump to actually stall when you close the faucet.  It might take a bit longer to build up pressure, but unless there was some weird way that increasing pressure moved the pump and kinked the line further, I'm not quite convinced.  Yet ;)  

Originally posted by GLBCamper Final(?) battery vs. pump tests. I charged the batteries overnight and started this morning (after an hour for decay) @ 12.90. First test per Paul, check voltage at all pump stages: Switch on, no demand = 12.89 Faucet on it ticked down about 1/100th every few seconds to 12.78 until I shut off faucet, with the switch still on ("stalled?") it ticked back up at about the same rate, landing back at 12.90. I double checked the amp draw this morning and got the same results. Demand = 3.5, No demand = 6+. Also, even with a fully charged battery the LPGD light goes out when pump switch goes on. BUT does NOT when connected to shore power.

My guess is the pump is defective. Many RV pumps, like the ShurFlo series, are thermally protected. That means they will disconnect from the 12V source when they get too hot. When this occurs the input current will drop to zero. Until then the pump will continue to turn even if they can't reach the cutoff pressure. They should not seize up and not run. You should be able to hear and feel the pump running.

Be aware that dealers don't really know much but they want you to think they do. Their usual response is that everything is OK and please go away. Don't let them get away with that answer. You know there is something wrong with the pump and it probably needs replacing. Also be aware that, even though your camper may be out of warranty, many of the components carry longer manufacturer's warranties. Check it out in your manuals or on line.

Good luck and keep us informed. Your feedback helps us too

The manual for my pump says adjusting the pressure switch should only be done by a qualified technician, so I think I have reached the limit of my capabilities (or at least my desire.) I made a service appointment with the dealer. The soonest they can get me in is three weeks away, but that's OK. At least they won't have to start at square one with only the symptom of "something's draining my battery" and for that I thank everyone on this board. I'll post an update when I find out what they had to do. THANKS to all for not giving up on me! I learned a ton and hopefully others will, too.