Water Pump Issue

[afd51]

Looking for help with an electrical issue with my '14 405FK. Intermittent problem with total loss of power to the water pump. Pump was recently replaced. Here's what I've determined so far. 1) Pump is OK. 2) no blown fuses or tripped breakers. 3) Relay was replaced with a new one. 4) when pump is DOA, if I unplug the relay, and then plug it back in, the pump will operate normally (until the next rime that it won't)

I'm attempting to download a few pics of the wiring and relay. It was located behind the panel in the water controls compartment.

I'm not able to figure out where to proceed next in troubleshooting this issue. Is it a switch problem (there are 2 switches for the pump), a bad ground somewhere, a bad connection in the relay socket, or something else totally?

Open to suggestions, and very appreciative of any advice. Thanks

[bubbles]

2 switches for the pump?

[BandJCarm]

Just 2 days ago at a rally, a guy was about to replace his water pump, and it turned out to be a loose ground wire. It was a B I O T X X X X X to get to it, though! But once it was looked at, the fix was easy. I'd check all wiring first. This was a 5th wheel, not a MH, but still worth looking at.

[SeaDog]

I understand you have dual switches for the pump just like a three way switch for a light, which makes me think those switches could be mis-wired to the relay. go online and down load the digram for how this relay works and ensure you have the connections in the correct pins. Just saw the post before mine and agree with that also

[Flybob]

The wire from the switch should go to either 85 or 86. There should be a wire from the other pin of the 85 or 86 set to ground.. Then there should be a wire from wither 87 or 30 to the fuse panel and the other of the 87/30 pair should go to the pump.

[afd51]

There are 2 switches that control the pump -- one in the coach at the "command center" and a second one in the water connections compartment. As far as the wiring goes -- all connections are in their original positions, and nothing has changed in that regard.

I assume that the white wire is the ground? Can I test it by clipping the ground clip of my test light to it and then touch some thing hot with the probe?

[Scrapper]

One question not asked yet is how long have you had the RV? If you had it before the pump was replaced, has it worked properly before the pump needed to be replaced? If yes to the second question, then maybe the relay is bad or the pump was mis-wired.

[afd51]

I bought the coach new. The pump was recently replaced by the dealer, but I can't positively say there is or isn't a cause/effect relationship to the new pump. The pump wiring seems pretty straight forward coming out of the relay -- 1 white wire, 1 red wire. If I hook the pump to an external 12v power supply, it works perfectly.

It is certainly possible that the dealer replaced the pump, when in fact this wiring issue was what was causing the problem all along.

[Scrapper]

Replace the relay, they don't last forever. The worst thing I ever had to troubleshoot on a million dollar car shredder was a small relay vibrating loose by 1/16th inch. Just enough that it lost contact in the socket. Found the problem by accident. Zip tie remedied the problem after 2 hours of testing.

[Flybob]

Did the dealer upgrade the pump? A larger pump might draw more current than the relay can support and the contacts could be burned. I would replace the relay. There is nothing special about that relay so if you can get a higher current 12V N/O relay with a 12V coil, you will be fine.

[afd51]

The relay is a week old. I suppose it could be defective right out of the box ?? Is there a way to test the relay? Are all of the inputs 12v, or are the switched inputs a lower voltage?

[Flybob]

If you put 12V on pin 85 and gnd on pin 86 you should see zero ohms between 87 and 30. When you remove the 12V, the circuit should open. Do not put 12V directly across 87 and 30 as it will be a short when activated.