Water pump wiring help September 25, 2022, 12:43:38 pm Good morning. I’m trying to help my 90 year old friend with his class A rig. He wants to winterize it so I pulled up the seat where the water pump lives, and I found that the pump wires are disconnected. I ran the pump by touching the two red wires together so we could pump antifreeze into his system. I’m still trying to figure out how to get his pump back into the switch loop. There’s a loose black wire coming out of the same harness as the red power wire, but the ground for the pump is already hooked up to a white wire that I guess is grounded. The on/off switch doesn’t affect the pump when I connect the red wires. He doesn’t remember why the pump was disconnected so I’m stumped. I’ll attach a picture in case anyone can give me a clue.Thank you,Larry 1 Likes
Re: Water pump wiring help Reply #1 – September 25, 2022, 02:19:25 pm Can’t help with the pump wiring, but I’d be concerned about reconnecting a water pump to such a large rig without knowing why it was disconnected originally, such as a leak in the plumbing lines somewhere.
Re: Water pump wiring help Reply #2 – September 25, 2022, 02:55:32 pm That is a legit concern. When we filled the lines to the sinks, shower, and toilet, the pump shut off when we closed the faucets. I did look for leaks under the sinks and didn’t see any evidence of anything. So if there are leaks, they are hidden. The pump doesn’t cycle as if it is losing pressure. Thank you for the reply.Larry 1 Likes
Re: Water pump wiring help Reply #3 – September 25, 2022, 03:13:59 pm I don't know about the black wire, it has a wire eye on it so it was probably connected to a stud somewhere . Im pretty sure the two red are originally connected as one of them comes directly off the pressure switch on the pump. If it were mine , I'd hook them up and give it some water or antifreeze and see what happens. Maybe check that black wire to ground with a meter and see if there is 12v present.Your kind of starting over from scratch if nobody remembers.Jon
Re: Water pump wiring help Reply #4 – September 25, 2022, 05:23:08 pm Hi Jon. Thank you for your reply. That eye on the black wire is my work. It was bare originally. It does carry 12 volts. What’s confusing is that there is already a ground wire coming from the pump to the white wire that has a big red wire nut on it. When I connect the two red wires and ground that loose black wire, the pump runs strongly with the switch in the off position and intermittently also runs in the on position. This is way beyond my experience.Larry
Re: Water pump wiring help Reply #5 – September 26, 2022, 04:22:32 am Hi Larry and Kathy; The two red wires at the output end of the pump connect the demand switch to power the pump. When pressurized the two red leads open up (disconnect) and shut off the pump. When you use water, (or a leak) allows pressure to drop, the switch turns the pump motor back on. The other end, bottom in your picture, has a red and a black wire. The black wire is a ground. Cars use red as positive, black as ground. Houses use black as a hot lead and white as ground. (Many times 12 volt appliances use white for ground and red for +12 volts, but no luck here). The red wire from the motor is connected to either red wire at the pressure switch. The black wire from the pump, you say, is already connected to a ground. That's good. The white wires are all grounds. The unconnected red wire at the pressure switch should be connected to the +12volts coming from the water pump switch. Likely this switch is farther away from the pump on a control panel somewhere and the black wire coming out of the harness should be the source of power from the control panel switch. If there is a fuse (ten Amps usually) it should be between the red wire at the pressure switch, and the source of +12volts out of the harness (black wire). Use a wire nut and cut off that ring terminal. There may be a fuse elsewhere, maybe near the switch, or it can be in the power distribution box along with all of the other 12volt fuses. One would likely be labeled as 'water pump'. Here is an instructional video. I didn't look at it all the way through. https://www.youtube.com/watch?v=dqROXlgt-lI&list=RDLVKtw7iyKgWdI&start_radio=1&rv=Ktw7iyKgWdI I hope this helped. RonB 1 Likes
Re: Water pump wiring help Reply #6 – September 26, 2022, 07:59:57 am Thank you, Rob. I’ll go back and take another look at the wiring after I reread your post a couple of times and watch that you tube video. I’ll post what I discover.Larry
Re: Water pump wiring help Reply #7 – September 28, 2022, 04:03:12 pm Thanks to all for the help. I’ve got the water pump sorted out. There’s an extra red 12 volt wire that doesn’t appear to be used so I capped it off and secured it.Larry
Topic: Water pump wiring help (Read 194 times)
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Topic: Water pump wiring help (Read 194 times)
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