New Holland 8010 low profile fuel pump randomly comes on when ignition switch is off

[rowellc]

New Holland 8010 low profile fuel pump randomly comes on when ignition switch is off. We have to unplug the fuel pump
after we use the New holland 8010. But I want to get this back to where it is supposed to be where we turn the key on and
the fuel pump comes on and when we turn off the ignition the fuel pump will not come on by itself.

Anyone have any ideas what the issue is here and what i can do to fix it.

We replaced the ignition switch but even with a new ignition switch we can start the tractor but the fuel pump still comes on when
the ignition switch is off and as we all know if we unplug the fuel pump and start the tractor the fuel injectors become air filled then
the the tractor does not start at some point and we have to drain all the air out which is a pain in the ***.

Why would the fuel pump come on by itself when the tractor is turned off? What can I do to fix it?

 

[WranglerX]

Start by looking what other electrical devices are connected to same circuit as fuel pump on ignition switch.... Would help if you had wiring diagram to work with, you may have to disconnect "other" devices one at time till you find the device that is causing random feed of power to pump also could be a issue in wire loom where the pump supply is being fed from two wires frayed and rubbing together....

Random or intermittent problem is usually hard to find unless you happen to stumble on something obvious or use process of elimination of all devices on same electrical circuit.......

Dale

 

[CoyPatton]

Dale’s info is solid!
Only suggestion I have to add is to trace the supply wire from the fuel pump back toward the ignition switch. Somewhere somehow, the circuit is being feed power. It is likely not before the ignition as the off position should stop any feed of power prior to the switch.
One place to check or change out would be a relay. Also check if the connector shows signs of heat damage.

 

[fishheadbob]

Dale’s info is solid!
One place to check or change out would be a relay. Also check if the connector shows signs of heat damage.

X2
....

 

[Tinhack]

Rodents love to eat the insulation off wire. Check all exposed wire harnesses. I would disconnect the battery until you find the cause. Shorted wires can cause a fire or costly damage.