Ford NewHolland 3930 wiring

[IisConfruzed]

I couldn't find the wiring diagram for my NewHolland 3930 on line. Once I got it I thought I'd share. My fuel shutoff solenoid wasn't getting any power, and I couldn't locate any info- ended up a $13 fix. Here's the diagram, info page and the supplement they came from.

 

[3930dave]

lis - if you are still around.... big thanks.

I have one myself, but stumbled across this tonight when trying to help a geographically remote 3930 owner.

Best Rgds, Dave.

 

[jimnix595]

What did you do to restore power?

 

[Wayne Todd]

Most definitely a big help. Thanks

 

[Wayne Todd]

Most definitely a big help. Thanks

 

[hairless]

Could you tell me how you fix yours. This is the same thing wrong with mine

 

[3930dave]

Could you tell me how you fix yours. This is the same thing wrong with mine

I don't know what other people did, but this is what I'd do:

Print out the schematic. The relay driving the fuel solenoid has a power feed that supplies the relay, and a control line driven by the ignition switch - both of those lines are fused.

Visually trace all the relevant wires first. Many times the problem is nothing more than mice-chewed wiring.

Start at the solenoid, and work backwards, looking for power present (Go/NoGo) - use a basic 12v test light - I prefer one with an olde school incandescent bulb - cheap, and IMO a better test load than an LED light. Start with the power feed side of the relay, that input line should always have 12v present.

Remember that the Ignition Switch needs to be in the run position to activate the relay control line and solenoid.

Rgds, D.

 

[hairless]

I don't know what other people did, but this is what I'd do:

Print out the schematic. The relay driving the fuel solenoid has a power feed that supplies the relay, and a control line driven by the ignition switch - both of those lines are fused.

Visually trace all the relevant wires first. Many times the problem is nothing more than mice-chewed wiring.

Start at the solenoid, and work backwards, looking for power present (Go/NoGo) - use a basic 12v test light - I prefer one with an olde school incandescent bulb - cheap, and IMO a better test load than an LED light. Start with the power feed side of the relay, that input line should always have 12v present.

Remember that the Ignition Switch needs to be in the run position to activate the relay control line and solenoid.

Rgds, D.

We have voltage to fuel shutoff solenoid and instrument when switch is on but loses all voltage to fuel solenoid and instrument panel when key is turned to start which tractor does crank over does not start because of no voltage to fuel solenoid. Do you have any suggestions

 

[hairless]

We have voltage to fuel shutoff solenoid and instrument when switch is on but loses all voltage to fuel solenoid and instrument panel when key is turned to start which tractor does crank over does not start because of no voltage to fuel solenoid. Do you have any suggestions

 

[3930dave]

We have voltage to fuel shutoff solenoid and instrument when switch is on but loses all voltage to fuel solenoid and instrument panel when key is turned to start which tractor does crank over does not start because of no voltage to fuel solenoid. Do you have any suggestions

The other way the fuel relay is driven is off the ACC line from the Ignition Switch - check the feed on that line, and that it is making it through the blocking diode, and fuse.

I don't know the exact sequencing behaviour of that particular ignition switch - meaning that I don't know for sure that ACC is live during starting.... it's the only other feed I can see for that Fuel Relay control line though.....

Rgds, D.