Wiring fat boy 7gpm

I purchased a Delavan 12v, 7 gpm, 100 psi pump to build a soft wash roof system. The electrical leads on the pump are 12ga. The pump is rated for 25 amp continuous, 35 amp surge. I spoke with Delevan tech services and they said their wiring recommendation was minimum 12 ga wire and 40 amp breaker. They had no idea where I could get an inline switch rated for the required amperage. It seems to me their 12 ga pump wire would burn up before it would trip a 40 amp breaker! I anyone has successfully used this pump in this application, can you share how you wired it? Also, what kind of on/off switch can be wired into the circuit?

Pump in a box is a 100 dollar upgrade from pressure tek. Well worth every penny.


I just used some wire I had laying around…wired to a $5 25 amp switch from the home improvement store and it’s been good now for every day use for 3 months. I’m no electrician but it’s a simple little pump

Get rid of the relay that comes with the pump and use a continous use solenoid. The relays are the weak point and will burn up causing you to stop the job and replace. Using a solenoid solves that, and also it acts as a switch so your toggle switch doesn`t actually need to be rated for 40amps or whatever. Probably a good idea to use 10 gauge wire. When I did mine I followed this diagram, I cant take credit for making it as I found it somewhere online a while back. Delavan%20solenoid%20setup

I used a marine battery switch ( I think it is 50A DC) and 10 GA wire. It’s not actually a Perko swith but it’s the same thing. I think it was about $25.00. I tried a 25A switch after blowing multiple fuses, I went to the heavy duty switch and it’s worked great since then.

What is the cost of making your own unit?

Too many variables depending on what you need. Pumps, hoses, fittings, reel?, gun, battery, containment system. You just have to figure out what you want and then price the components.