Water pump issue and voltage drop

[Heath]

Hi,
Having an issue with my MH. The water pump was acting up, getting noisy, then finally quit. Turned out to be one of the posts on the pressure switch assembly had corroded and actually broke off. So I ordered a new switch assembly from Amazon and installed it with no issues (took out pump, removed broken pressure switch, installed new one, put pump back in).

Now the pump won't prime (or build pressure in the lines). Water just sputters from the tap. I tried the usual suspects to correct this...tank is full, all taps were open, including the outside shower, to bleed the air from the lines, tried opening low point drain, opening water heater pressure relief valve, etc. I haven't been able to identify any leaks on either the side of the pump.

I also tried disconnecting the suction line from the pump and hooking it directly to a hose pulling water out of a separate jug. Suction is okay, but not great. Still won't pressurize lines.

So then I started worrying about the pump itself, wondering if the failing pressure switch did some harm. I found a voltage drop on the DC fuse panel for both the pump/radio fuse and at least one other fuse (rear attic fan I think). But other connections seem fine. So it seems like the pump isn't getting the voltage it needs (less than 11 volts right now). Not sure if that is my problem, but it sure doesn't seem right, so I'm wondering where I can look now to troubleshoot.

The batteries themselves seem to be fine. They run the inverter with no problems and provide good voltage in other places I check.

FYI - A couple weeks ago I disconnected the 2 house batteries to add some water because their performance had dropped off some. Water level was over the plates, but I topped it up. It didn't seem to help much tho. Maybe I did something when I reconnected the batteries? The pump was pressurizing okay after that, tho, so I'm having trouble believing everything is related.

Just can't get the pump to pressurize and I'm seeing that isolated voltage drop. Any ideas?

[Hivoltage98]

Did you set the pressure switch?
What's the voltage with the pump not running and what is it when running?


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[Heath]

Thanks for the reply.

Nevermind about the voltage drop. I was getting a low voltage with the pump switch off, but when I turned it on, it was normal. That's at the DC fuse. I also read the voltage coming from the pressure switch to the pump motor and it was normal. I'm not too savvy when it comes to electrical. Anyway, I feel better about the wiring in the coach, but it puts me back to the drawing board with the pump.

As for setting the pressure switch, no I didn't. I figured the factory setting would be good. No? It's the center screw that you use for adjustment, right? I tried turning it a couple times, but it didn't help. I don't think the cutoff setting is a factor, tho. The pump just doesn't seem to be creating enough suction. I tried using a city hookup to fill the lines and get rid of all the air and then using the pump, but that didn't work either.

I'm open to any more suggestions.

[Heath]

Got it fixed... Dumb luck I think. Took the pump out, took it apart, looked at the valves and drive assembly. Nothing clogged or worn. Kinda messed with the intake/suction lines... They were a little kinked coming in and out of the valve controls, but I don't think I made it much better. Put everything back together. And it worked like a charm.

I would have liked to know what actually made the difference, but I'm not complaining.