Hot wiring fuel solenoid JD 770

[Brianksnyder]

I have a 1994 JD 770 compact tractor, with a Yanmar 4cylinder diesel engine. Over the years the mice have eaten portions of the ignition wiring harness, so I resorted to wiring a simple push button from the two wires on the starter. That has worked well until now. When I turn on the key the fuel solenoid does not engage, and initially I suspected a problem with the seat safety switch, so I warped a zip tie strap around the switch to make the contact, but still no go. I suspect there is more damaged wiring and would like to know if its possible to hot wire the fuel solenoid to a simple on / switch. There are three wires leading the the solenoid, one red and two yellow. Does anyone know if this idea will work, and which wires need to be switched?

 

[zzvyb6]

Part of the problem may be the extra cylinder in your motor compartment. Just about all 770s have 3 cylinder diesels. My 1070 came with a 4 cylinder, though.

That being said, the fuel solenoid has a ground, "pull-in" and "hold-in" circuit. FYI: there is a "pull-in" relay (plus a time delay element) and on some machines the circuit has the hour meter in series. So, I suspect you would at least need a "hold-in" SP switch and a "pull-in" momentary switch, sorta like an ignition switch on a gas motor.

 

[Brianksnyder]

Sorry my mistake, it is only a 3 cylinder. Ant ideas on where I can get a wiring diagram, or how to determine what the colored leads are on the solenoid?

 

[joecdeere]

there are a couple of different wiring setups dependent on the serial number, shoot me your email and I'll send you a PDF of the complete tech manual with all the wiring in it

Joe

 

[gengine]

Part of the problem may be the extra cylinder in your motor compartment. Just about all 770s have 3 cylinder diesels. My 1070 came with a 4 cylinder, though.

That being said, the fuel solenoid has a ground, "pull-in" and "hold-in" circuit. FYI: there is a "pull-in" relay (plus a time delay element) and on some machines the circuit has the hour meter in series. So, I suspect you would at least need a "hold-in" SP switch and a "pull-in" momentary switch, sorta like an ignition switch on a gas motor.

This is exactly right, a "pull in" wire and a "hold in" wire. That being said, I am a mechanic for two rental companies and run into many different setups. In my experience, the best way to remedy this is to call JD and get a new harness, as it will solve issues that haven't arrived yet. A few of our machines have been "fixed" over and over and over, each time because one thing would be repaired but then another would come up. I've found over time, it is pay me now or pay me later. The more you rig things up now the more you will be miserable in the future. If you fix it right the first time and prevent it from happening again, you will not have issues in the future, but you may never know what you have saved yourself in parts and headaches. As for the mice, buy the blocks and not the pellets as far as poison goes. The mice will stash the pellets and eat them later. The blocks will get stashed also, but they ingest some when they are taking bites to haul off and stash.