Didn't know they'd run backwards

rrlund · Jan 2, 2015

I've got a 12v fuel transfer pump for diesel fuel. I hooked it up today to put fuel in a tractor and it ran,but it wouldn't pump. I thought,great,must be ice in something. It's supposed to be a little warmer the next few days,so I just hung up the hose and turned it off. I went to unhook the clips and had the red one on the ground. I switched them and it pumped just fine. Old age,gotta love it. lol

LME · Jan 2, 2015

Still celebrating New Years eve??

Case Nutty 1660 · Jan 2, 2015

done myself more than once,,, I have one pump a Mico that has the pump at the bottom of the stand pipe, it will pump both ways but in rev it is 1/4 of the flow, I hook my trailer tank pumps up with the clip colors reversed, sure stopped the gas from disappearing during harvest when I left a trailer in the filed lol

Tom in TN · Jan 2, 2015

Randy,

But the real question is, "Do you now have more diesel fuel in your big diesel fuel tank than you had before?" Now that would be a good fuel transfer pump.

Tom in TN

Bob · Jan 2, 2015

They are typically permanent magnet motors, which explains why it would run backwards.

FLOLDFORD · Jan 2, 2015

Had a fellow bring a nice 26 ft fishing boat this past summer to repair the livewell pumps. He had paid a local marina big money to replace both pumps and switches. next trip offshore neither pump would work they would run but not pump. Took me about 15 minutes to reverse the wiring that they had backwards. Funny thing was the leads had big tags on them marked positive and negative and they still got both of them wrong. I told him to go get his money back for that job.

John B. · Jan 2, 2015

Bob here is correct. Permanent magnet motors will run backward if the leads are hooked up backwards. By reversing the current in the armature when the leads are hooked up wrong causes this. But the field magnets' magnetic field stay the same.
Old starters will run the same direction because the current gets reversed in the armature and field windings.

jeffcat · Jan 2, 2015

do you have any idea how many battery chargers and boiled batteries my old man did???? How many time s do you need to tell someone the red goes to the plus and so on. I finally started to paint the top of the positive post red so he would get it.

NEIADan · Jan 2, 2015

Been there. I have to remind my help that on the tractors we have with generators are positive ground. Really confuses some.

john *.?-!.* cub owner · Jan 2, 2015

Wait until you come across a gas engine that will run either way, that will warp your thinking till you get used to it. For reverse the old 2 cycle gas carts simply spun the starter backwards and it fired right up and ran. Not quite as powerful backwards, but worked.

kruser · Jan 2, 2015

I'm not going to say anything - Just in case Red Green is lurking!

Didn't know they'd run backwards

rrlund

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LME

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Case Nutty 1660

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Tom in TN

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Bob

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FLOLDFORD

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John B.

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jeffcat

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NEIADan

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john .?-!. cub owner

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kruser

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