run yourself a couple of wires from the battery to a quick disconect plug in the bed of the truck.

i wouldn't want to run that much stress throught he ciggarete lighter. the aren't designed to handle that much of aload. it takes 3 times the power to start an electric motor than to keep it running.

 

I am rethinking my contraption with the great ideas here...

This is what I have done with the wiring and think Hvytrkmech may have hit a chord.... Here is how it is wired.



Hub

 

Does your switch have a light in it? Otherwise, there is no need for the ground to go to the switch. Make sure that there is no continuity between ground and either of the other two terminals on the switch. For the record......I still think the cig. lighter is to light duty for the application though.

 

Yeah, if you have the tow package, I like the idea someone posted about getting a 7 pin RV plug.

I believe the battery charging wire is 30 amps, so I'd probably mount a smaller in-line fuse to protect your pump, if it were me.

 

Is this the actual schematic of the switch? Usually the center pole on a spst lighted switch is for the ground to light the led within the switch. If the center pole is indeed ground the just run a ground wire from that and tie it too the other ground, do not ground the motor through the switch.


Tim

 

The switch has a LED on it, Guess I should have mentioned that part. Should I isolate the ground from the pump?

Leaning towards the trailer connector on the truck but trying to save some cash.

Hub

 

You do not have to isolate the pump ground. Ground the incoming neg. to the metal mounting plate of the pump motor, tie the pump motor ground to the same ground, run a ground wire from the center pole of the pump on/off switch to the other grounds at the metal mounting plate, just use a long enough bolt to anchor them all together on the base plate. I am assuming that you mounted the tank inside the box so it can be removed from your truck easily, so with that being said it is imperative that you have an excellent ground and power lead on your main feed cable. As others have stated the truck 7 way is an excellent resource for you to tap into, you can buy a 7 way male connector at your local auto parts store for around 5 bucks. Then just wire a black 12 gauge wire to the 7 way ground, and wire the red cable to the constant hot trailer pin, all for less than 15 dollars with more power than you need and an excellent ground. Make sure you wire a fuse for the rated draw into the positive side at the motor.

Nice job on the fab up of that system.




Tim