An electrical gremlin

[ageless]

I am replacing a 32v livewell pump with a 12v. The wiring from the breaker box to a junction box by the old pump has a (+) , a(-), and a ground. I have a 12v bank that I ran a + and - from to the existing wiring at the 32v panel. I get 12v readings at the pump but it won't power up. I've connected it directly to the battery to ensure it operates and it does. I'm 100% sure I have solid connections but I can't get it to power on. What am I missing here? Do I need to have the (-) and ground BOTH connected to the (-) side of the pump?

 

[Scarlett]

Should only need one negative, but use a meter to make sure that one of those is indeed hooked to negative, one might just be a dead unused wire. John

 

[Pascal]

If the pump works connected to the + and - of a battery then you don’t need ground. That’s pretty rare on a DC pump anyway

Now this part of your question is confusing “ I have a 12v bank that I ran a + and - from to the existing wiring at the 32v panel.” Not sure why you d run the new feed from the 12v bank to a 32v panel. For the switch? What switch are you using? A switch on the 32v panel but connected to the 12v feed instead?

If you really have 12v at the pump it should work. What kind of pump and where is the on/off switch?

 

[ageless]

If the pump works connected to the + and - of a battery then you don’t need ground. That’s pretty rare on a DC pump anyway

Now this part of your question is confusing “ I have a 12v bank that I ran a + and - from to the existing wiring at the 32v panel.” Not sure why you d run the new feed from the 12v bank to a 32v panel. For the switch? What switch are you using? A switch on the 32v panel but connected to the 12v feed instead?

If you really have 12v at the pump it should work. What kind of pump and where is the on/off switch?

I disconnected the (+) wire from the 32v panel and connected it to the (+) coming from the 12v battery. I disconnected the (-) from the 32v panel and connected it to the (-) coming from the 12v battery. Without question I have a 12v reading at the pump. I initially ran the (+) to a toggle by the pump but when I had no power when I turned it on I bypassed it to ensure it wasn't a bad switch. The 32v pump that was in place worked as it should until it's demise and it had the same (+) and (-) leads I'm using

 

[tonytrakovich]

With the pump disconnected, check the voltage near the pump. Should be 12v. Then temporarily connect the pump by twisting the wires together and test the voltage. If it is zero then there is a wiring problem. If it is 12v then it is a pump problem. Float switch on the pump?

 

[SKYCHENEY]

Maybe the 32v pump was just fine and its a short in the wiring from the panel to the junction box. Get a multimeter and make sure you have power back there where you're hooking the pump in.

Then put 32v to that old pump and see if it runs. If it does, you can ship it to me

 

[Cricket]

The DC "negative" from both 32v and 12v systems should be tied together.

 

[dsharp]

Did you cut the wire back a little where you crimped the pump pos. and negative? I've seen more pumps replaced that ended up being a bad connection or corroded wire that was dangling in the bilge. It sounds like a bad ground. It will read 12 volts until you put a load on it.