I have a 1998 U320 and my 12v water pump will not turn off , the green light stays on at all three locations and when you push any one of the 3 locations it will not turn it off . So I was just wondering if someone could tell me the location of the pump please . Thanks
On a 99 U320 it is located next to the water manifold located in the right side bay just in front of the right rear duals. Not sure if the same on 98?
Pump
On my 98 U320 it is in the bay described by Muskyman. It is behind the Aqua hot cozy.
It is easier access if you take down the fiber board panels in the bay and remove the shelf over the pump.
Is the pump running all the time or are the lights just on?
The lights and the pump are powered through a latching relay (mine is behind the white fiberglass panel on the wall in the big bay).
Pushing any of the momentary switches closes a short connection to ground which latches or releases the relay.
You could have a stuck switch or a ground fault somewhere.
The latching relay wiring looks like this. (The fill valve here is your pump). The #2 connection will remove power from the pump and lights. The A2 connection is the grounding switch connection.
Yes the pump kicks on and off every once and a while so yes it's on . I appreciate all the response I will look tomorrow and find it , also thanks for relay location as well . I've owned three of these coaches in the past and I totally disassembled one that generator caught fire . I converted it to a fifth wheel for 18 wheeler . I just recently pick up this 98 and having to remember this all over again , lol Thanks Again
Brian, good to hear from you. You probably don't remember me, but when I was looking for my coach, I drove down from KC to look your coach before you turned it into a 5th wheel. It was a very nice coach. Welcome back and don't be a stranger.
Larry
If the pump cycles on once in a while with no faucets open, you need to find the LEAK. Particularly important if it is leaking in the wet bay, as that water finds its way directly to the rear bulkhead.
And if you don't find a leak, isolate the pump as they sometimes have the same symptom.
I remember posts on that project a few years back. If you get a chance sometime, post some photos. It would be great to see it hooked up and the modifications you had to make. Thanks
jor
"If the pump cycles on once in a while with no faucets open, you need to find the LEAK."
Might the leak be an AIR leak? I have a pressure tank, which provides a bit of pressure without the pump. Last year I replaced it because it wasn't holding pressure. I believe that the pump pressurizes that tank, as well as providing the main pressure for the water lines. That pressure tank won't hold pressure indefinitely, so if you aren't using water and have the pump circuit energized, the pump will eventually come on to bring the pressure in the tank back up, won't it?
David,
Not sure I understand your point.
The ACCUMULATOR has a diaphragm in it. As long as it is undamaged, it will maintain pressure forever. And, it is easy to test-- at least on the majority. They have a schrader valve (like on a tire). Turn off shore water, turn off pump and open a faucet to depressurize. Use a tire gauge to check PSI. Any water comes out-- accumulator is bad. Proper PSI is CUT-IN PSI less 2 PSI. So, for many pumps 23 PSI.
As craneman said it could be the pump, the check valve could be gone.
Brian, I'm sure you have fixed this by now but....that is the switching relay causing that problem. One of the points has fused closed.
If you have the Finder relay unit they are easy to get, but the old automotive cube style relay is a little harder to find.
After many hours of searching though... this is the one that FT used on my 1998. I had the same problem, so figured if someone else is searching for the answer it would be useful.
SAR9200, originally made in Austria, then copied in Germany, now made by Standard Motor Products with a new number. LR35
Amazon.com: Standard Motor Products LR35 Relay : Automotive (https://www.amazon.com/dp/B000C83NSG?psc=1&ref=ppx_yo2_dt_b_product_details)
This is what is used on later (2001) coaches
Finder 20.23.9.012.4000 1NC + 1NO 16A, 12V DC Coil, AgSnO2 Contact, 2 Step... (https://amazon.com/gp/product/B00CKRHU2C/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
You can use this one with a built in timer to turn off the water pump after a user setable time.
GAEYAELE 1PCS GRT8-M 16A Multifunction Time Relay with 10 Function Choices... (https://amazon.com/gp/product/B07CH7KJ39/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)