Fatboy(delavan 7870) Pump

Good day peeps,
I have seen the post on here before with a Fatboy 7gpm pump wired to a solenoid instead of the 30amp fuse that pressuretek sends with their pump in a box. Would someone please upload a few pictures of how it looks wired to the solenoid and give me your thoughts if it works better than the 30 amp fuses. I’m currently going through 2 fuses a week.


I found your diagram here in less than 5 seconds with a Google search. Others here will spoon feed you, just give them about 10 mins lol

I’m looking for an actual picture of the wiring and not the diagram, but I appreciate your comment, it was very thoughtful.

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What size hose you running?

@dperez :wink:

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Don’t see one yet but this may help:

  1. 10 gauge red wire from battery +12 V to one end of 40 amp circuit breaker (CB).
  2. 10 gauge red wire from other end of circuit breaker to a switch.
  3. 10 gauge red wire from other end of switch to input of solenoid.
  4. 12 gauge red wire from input of solenoid to one end of delavan pressure switch wire.
  5. 12 gauge black wire from other end of delavan pressure switch wire to solenoid’s coil +12 V terminal. (In the past Chuck, I accidentally said red)…
    ( some solenoids show a positive and some do not care.)
  6. 10 gauge red wire from Delavan +12V wire (red) to output of solenoid.
  7. 10 gauge black wire from battery -12 V to solenoid’s coil -12 V terminal.
  8. 10 gauge black wire from battery -12 V to Delavan ground wire (black) to output of solenoid.

This thread discusses it further.

Thanks guys. I’ve read that thread but I was hoping for a picture.

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So you have no interest in why it’s blowing fuses, you just want a photo to decide what it looks like?

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Do you have a Fatboy pump?

3 on the trucks and 4 on the shelf.

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Unlike what the other posters think, I did my research prior to setting up my Softwash system and I know the usual suspects on why these pumps fail and blow fuses.

2 batteries in parallel(charged nightly)
3/4 supply hose
5/8 applicator hose
Remco accumulator tank
Pressure screw set to minimum psi

I read that post a few months ago and thought I would give the solenoid a try before I try a new pump and use this as my sh transfer pump. All I wanted was a picture of it set up with a solenoid.

Good lord @MuscleMyHustle you must really be a masochist :grimacing:

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We do a lot of roofs, we don’t do shopping carts and shipping time, we stay replenished garry lol

If you got two you only have one. And if you got one you have none.


I’m so confused now. That diagram would serve as a picture. With a picture you wouldn’t be able to see where any of the wires go to, only the few that made it into the shot. I could see your point it was a schematic where you needed to know how to read electrical symbols.

We do a lot of roofs too, difference is we do 'em good…hahahaa

One of today’s jobs


I wouldn’t dare compare myself to you garry you are a Goliath i am a little boy sitting on a bench eating an ice cream in the rain. That came out great :ok_hand:.

Thanks. It was another hot one, think I drank about 2+ gallons of water and Gatorade in about 4 hrs.

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Mine’s set up with a solenoid…I’ll try to remember to get a picture for you tomorrow morning.

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@MATTC Here are some pictures for you. Hopefully between the pictures and your diagram, you’ll be good to go. (Please ignore the quick-connect plugs…they are only there to make pump swaps quicker, so don’t let their presence confuse you)

image image image image image

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