Water pump keeps blowing fuses

[topperharley]

Last winter I went to winterize my RV and when i turned the water pump on, the fuse blew. I tried another fuse, same result. So after a little research I saw that some people had luck changing the pump switch. So I ordered one, replaced it and voila, it started working. I guess these switches short out internally.

So now i'm in the process of dewinterizing and sanitizing the lines. i just filled my tank for the 2nd flush and turned the water pump on and the fuse blew again. I'm going to order a new switch, and actually have a whole new tank monitor system that i can probably use for the moment as a replacement switch, but i'm worried theres another issue. i understand theres a relay because the power coming out of the switch is definitely not 12v. Is there a way to test the relay? what else could be causing the fuse to blow? The first time this happened i disconnected the pump and jumped it with my 12v battery jump-start box and it worked fine. I went through sanitizing and the first flush before this started happening again. very frustrating to say the least.

[SeaDog]

What rig do you have make/model. I have not encountered a relay associated with water pumps on rigs, this in no way means some don't have them. I think I would search the power going to the switch and make sure it is at the proper level. Check all the wiring to and from the switch.

[topperharley]

its a 2019 apex ultra-lite 300bhs. i've check all the wiring connections, except the wire that goes up to what i believe is a relay. i suppose i'll have to open that area up and see whats going on.

Its just weird how a new switch solved the problem, but now its acting up again. i guess worse case i can run new wires and hopefully solve the problem that way, but thats a pain.

[topperharley]

Update: so i traced ask the wires and everything looks good. I also tried a different switch and it still blew the fuse. So then i had the idea to disconnect the pump and turn the switch on, thinking that if there's a short after the switch it'll pop the fuse, but it didn't. So this tells me that the pump is bad. I will be ordering a new one and seeing if that is indeed the issue

[SeaDog]

If its a shurflo pump before you order a new one take the three screws the hold the pump to the motor and separate them and run the motor it to see if that is actually the problem, may be a binding in the pump end bearing and you can buy the entire pump end with the pressure switch for $49 bucks or so. Just replaced one at my shop.

[topperharley]

Originally Posted by SeaDog

If its a shurflo pump before you order a new one take the three screws the hold the pump to the motor and separate them and run the motor it to see if that is actually the problem, may be a binding in the pump end bearing and you can buy the entire pump end with the pressure switch for $49 bucks or so. Just replaced one at my shop.

It's a artis Model: PDS1-130-1240E. I'll be taking it out soon and investigating more

[bubbles]

Just curious. Is the fuse before the switch or after?

[topperharley]

Originally Posted by bubbles

Just curious. Is the fuse before the switch or after?

Fuse is before the switch. So if there was a short before the switch, the fuse would blow immediately.