Farmall 400 electrical black hole

BarnyardEngineering

Well-known Member
Location
Rochester, NY
Yesterday while spreading manure, the 400 up and quit dead in its tracks. No electrical whatsoever. Starter won't even click. Up until this point it has always started instantly and run great.

Tipped up the seat and found corroded battery terminals, so that must be it, right? Cleaned the terminals, no change.

Put on the jumper cables, no change.

Went direct to the starter with jumper cables, not even a spark, even with the main battery cables disconnected. Can't even get a spark just tapping the two jumper cable clamps on the tractor frame.

I've seen and studied a lot of problems but never seen a complete electrical black hole on a tractor, where nothing will even make a spark. It's like the laws of electricity no longer apply.
 
Have you checked battery voltage? If the terminals were corroded maybe it wasn't getting a charge and it simply ran out of juice from the ignition draw.

Have you tried jumping it from a car/truck/other tractor?
 
It sounds like something is wrong
with the jumper cables. The 400 has a
fuse in the dash that I've known to
have a problem. If you look at it the
fuse looks good, but the solder in
the ends melt. It could be all the
heat from the hydraulics.
A nice update is to eliminate the
fuse in the dash, splice those wires
together. Get a modern fuse holder
and put it on the solenoid where the
power comes from.
By turning on the lights you can
identify if the circuits are working.
 
Did you check the ground cable where it hooks to the frame?Sometimes they get corroded there and the whole system goes dead.
 
Internal battery open. Put a volt meter on it and it will show way low volts from a tiny conductivity. I assume you didn't lump it from a truck or
external battery. Jim
 
It died as far from the shop as is humanly possible. Only had basic tools to work on it. Don't know the condition of the battery but it doesn't matter because we took it right out.

Tried to jump it from the truck. Nothing, not even a click. No lights, no ignition, no solenoid. Nothing.

Took the 400's battery right out of the tractor and tried to jump the starter direct from the truck. Nothing, no spark, no click, nothing.

Took the same jumper cables and same truck, jumped the Cub off no problem.

You would think even if it wasn't enough to turn the starter, jumper cables would give you SOMETHING. A click. A spark. We get... nothing.
 
With the jumper rubbed into a edge of the starter motor, touch the starter post where it enters the starter case (bolt). If nothing, the brushes are
not touching the armature (series wound motor). If it cranks, the starter motor has lost its ground to the bell housing. Jim
 
With jumper cables from another vehicle connected to the battery cables it should take less than 2 minutes with a test light to see where power is getting lost.

Could even be an "open" between one of the 4 battery cable end terminals and the actual cable.

Hop to it!
 

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