Replaced the controller switch. Pump works when I ground it. What do I check next?

Thanks

Does your RV have multiple pump switches?
Mine has one up front in the kitchen, one in the bathroom and one out side for the shower.
If it does, maybe one of the other switches is bad or just off.

There is one in the kitchen and one in the bathroom and I don't think there is another one but I will look. The switch in the bathroom stays in the up position and if you push it down it comes right back up. I will check that switch and see if there is another one. thanks

I'm not familiar with the controller...…

A pump would normally have 12 volts positive on the red wire from the switch(s) inside and the black is grounded.

The 12+ is run thru the pressure switch on the bottom of the pump.

Turns pump on and off …..

Your pressure switch may be bad...

I assume the black ground wire goes up to the connector on the controller.

B+ should be on the red wire going into the pressure switch....anytime the switches are on inside...

B- should always be there.....

A volt meter is all you need to tell whats wrong...

Yeah the black ground wire goes to the connector on the controller. Its gettin 12+ and when I unhook the black ground and ground it, it will run.

Scott,
Is all of the wiring the same as what was there with the previous controller, (This was a "plug-n-play" replacement)?
From what my eyes are seeing, (could be wrong, lol), there are 4 terminals on the controller, marked as (L-R) +12V, Sw(switch), Load and Ground? Is the heavy green wire connected to the Gnd terminal? Where does the black ground wire (from controller area) come from? Is it attached to the Gnd terminal on controller?
Like Rich said, this should be fairly simple to troubleshoot with just a multi-meter. If you ground the black motor wire (to chassis ground) and it runs, but it does not when connected to that short ground wire connector, it sounds like the pressure switch is correctly sending a call for pump signal, but the controller is not providing a proper connection to chassis ground. Is that bulkhead made of non-conducting material, or metal? Might want to measure the resistance (Ohms scale) from the Gnd terminal wire to actual chassis ground.
Just kind of tossing out some thoughts as they bounce into my head...

Yeah it was a plug n play replacement. The black ground comes from the load terminal. There used to be an aquahot in the RV and the heavy green must have been for it and it looked much better than the ground that was connected so I used it. I was using the old ground to operate the pump manually.

It might be the pressure switch now that I think of it. When I winterized it, I noticed that it wouldn't stop so I just unplugged it for the winter then this spring when I got it out and plugged it back up, it wouldn't work at all.

So the pressure switch is on the pump and kills the hot side? Hmmm, so why doesn't it run all the time now when hooked up, if it is the pressure switch?

Scott, it should run all the time, (at least until you have pressure, if it is working right). And yes, the black pump motor ground wire should be connected to that short wire on the load terminal.
My big question now, is where does that large green wire on the Gnd terminal go to? Measure the resistance from it to the chassis, should be a solid (dead short/zero ohms) chassis ground, or a battery ground wire. All the rest of the wiring looks correct. Is the original ground wire still there somewhere? If so, try going back to that instead of the green wire.
Oh, one other thing - That latching controller needs to "see" an input from one of the onboard coach pump switches. So *after* everything is hooked up properly, pump should not turn on until one of the switches is hit. They are designed to respond to even a momentary input switch signal, like from a pushbutton, and "Latch" into the "On" mode until turned off.

This message has been edited. Last edited by: FootbrakeJim,

It’s possible they used ground circuit for switching instead of the positive side. Just a thought.

The tank fill valve has to be in the right position on mine or it will never shut off or build pressure

quote:

Originally posted by green1:
It’s possible they used ground circuit for switching instead of the positive side. Just a thought.

Yes, that is exactly what the controller is for. Pump has constant B+ 12V supply, controller activates it by completing the Ground circuit.
And as for the pressure switch, It is either working properly, or stuck "on" (closed contacts), if it was not closing, your pump would never turn on. Like J.R. says, valve needs to be set, and you must have no leaks on any pump plumbing, or the pressure switch will not turn the pump off. Trapped air in pump will cause same, need to purge all air from lines & pump. But for now, I'd be looking for a good solid ground for the controller.

This message has been edited. Last edited by: FootbrakeJim,

Yeah it is just unhooked in the pic where I was manually grounding it. The large green goes to a chassis ground close by. I will check it but I think it is a good ground. The original is still there but the pump doesn't work with it hooked to the controller either. I think both are good grounds its just the green one looked better to me.

The red wire IN at the bottom of the pump is to the regulator switch....B+ power

The red wire up to the pump motor is power to the pump once the pressure switch closes across those 2 wires...

I know zero about the controller. Never saw one....

I'd have to Google it and find out what its for before I could say what it does or doesn't do....

I am guessing its just a relay.....You turn the switch on inside and it powers the pump circuit....

My MH has the same pump or one similar.....NO controller.....

I take it out every winter.....Water can and did collect down in the bottom and froze and cracked it one winter....

I replaced the cracked part and the cracked filter and keep a spare pump on hand....


My MH has a battery connection/ switching device I also never saw.....a B.I.R.D. Made me crazy until I read what it does and why strange things were happening....Made prefect sense once I read what it was and does....

Knowledge is power......LOL

It sounds like the Load terminal is not giving you a ground signal.

Is the +12v wire hot? Does the wire going to the 'SW' terminal have a good ground when the pump switch is on?

Yes I found that.

It allows multiple switches to turn pump circuit on and off.

Intellitec makes battery switches that latch on or off...That means they connect or disconnect and are not energized after the switch is released..

The diagram does not show what is going on inside the controller.....

Since you changed it.....your issue is not likely the controller unless you have it wired wrong....

Are your switches MOMENTARY on/off.....?
means they spring back from either on or off....

If they do then the controller is similar to an Intellitec battery connection relay......bi directional......they change polarity inside to move contacts one way or the other.....closed or open.....

Sounds confusing and it is but not really.....LOL

Yeah the switches are momentary.

OK, and the controller is new? Try reconnecting it again, and hitting all the pump switches in the coach.
When you were grounding the pump "-" wire, you are bypassing the controller completely. The same red B+ wire feeds the controller and the pump (thru press Sw), so all pump needs is a ground, which the controller is supposed to provide. So you know the controller is getting power, and if you are certain it is connected to a good chassis ground, the Load terminal is the path for the pump "-" wire to complete the pump circuit. It is similar to a relay setup. Then the only additional thing you need is Switch terminal input. And you can test that function easily - The switch input terminal is activated by a "low" (Ground) signal. So you can pull the purple Switch wire off, and attach a short test lead to that terminal, then find a convenient place to ground the other end of the wire, (Gnd terminal), and it should activate the pump by providing a Ground for it through the Load circuit.

Found the 3rd switch, works great now. The old controller cover was melted and looked like a fire hazard to me so $29 from amazon not too bad of a f up.

Newbie RV guy sorry for wasting your time lol

It was a good thread for me.
I learned about a new device I’ve never seen.
Trust me MH’s are an adventure in learning !
I try to stick to generators and transfer switches but I always get caught up in other problems that owners ask me about.
I’ve had some really difficult problems to diagnose mostly generator related.

Every motorhome is different !