I have been fighting with a problem for maybe over a year now but can't figure it out. Thought I would post it here to see if anyone may have a clue. Flojet tech support lately has been unavailable for some reason. I had a VSD pump quit I think last year sometime and it was still under warranty so they sent me a brand new model pump as a replacement. I removed the accumulator tank because it is not needed with a VSD pump. All seemed well until I was in a rest area outside of Tallahassee one day and the water quit. Went out to check the pump and it was very hot to the touch. Thermal breaker cut it off. After it cooled off it worked again. Contacted Flojet and they sent me another brand new pump. Installed it and all was well until I noticed that it was not shutting off under battery power. Essentially what I figured out is that it will work fine as long as the coach is plugged in under charge. Floats around 13.2VDC. But when it is running on the 12 VDC battery power it will not quit running. It sort of just grumbles along at a very slow speed. My house batteries are brand new so that is not the problem. I also yesterday plugged it directly to the chassis battery with a jumper and it works fine. I have looked very closely at all the connections and the power switch and everything seems tight and no issues. Voltage at the wiring is good. Cleaned and checked the ground. Still it is baffling me. The pump does have a small pcb that controls it. It maybe very sensitive to something. Anyone else ever had or heard of this problem? That was way too much rambling sorry.
Mark
Is the wire gauge the manufacturers recommended size? Only thing I can think of is that there wire gauge supplying the DC voltage is too small.
Roland
Maybe the load is to much (short in wire)?
The gauge wire I used to jump it to the chassis battery was a thin wire and it worked fine. All the coach wiring is much thicker.
Mark
Had something like this happen with our 94 U280, I had to install a relay in between the pump and the latching relay. The latching relay turns on the pump relay. Latching relay didn't like the vsd pump. It's been fine now for 3 years. Hope this helps.
I had a VSD pump that would constantly run (just barely) and get hot to the touch. There was a set screw under a plug. Turning that screw 1/4 turn prevented the pump from running all the time and overheating. It worked great for many years after that.
Check and see if you feel any vibration at all with hand on pump and no faucets open. If so, try turning the screw (if yours has one) a small amount.
Thanks for the idea's I will look into both of your resolutions.
Mark
Tried to adjust the pump but it did nothing. Will look at the schematics but I don't believe my coach uses a latching relay for the pump. Just has one switch in the kitchen.
Mark
Wish we'd had this info a couple of years ago.... Thanks Dan!
Mark, if you can start the pump from multiple locations then you probably have a latching relay. Look at your schematics.
John M
John,
Only one location in the coach.
MAZ
Mark, there should be a latching relay under the white cover in one of your bays.
Bill,
Wouldn't a latching relay require a momentary switch? I just have a on and off switch.
Mark
Mark,
Try and follow the wires from your pump back to your switch and power source and check their condition. Maybe a mouse or something got in your coach bays and chewed on some of your wires.
John M.
Mark, the 99 must wired different from my 97
Just wanted to show the conclusion on this problem. Today I installed a finder relay and a momentary switch and the pump now runs great and shuts off properly. It looks like the previous owner removed the latching relay and hot wired it through an on/off switch.
http://www.newark.com/finder/20-21-9-012-0000/contactor-spst-no-12vdc-din-rail/dp/08X7043
Rv Designer Collection S321 Black 10 Amp Momentary-On/Off Switch 601320113212... (https://www.ebay.com/itm/Rv-Designer-Collection-S321-Black-10-Amp-Momentary-On-Off-Switch/123044468936?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)
Regards Mark