MH Pony Wiring

   / MH Pony Wiring #1  

looch

Veteran Member
Joined
May 30, 2001
Messages
1,038
Location
QC, Canada
Tractor
CK2620 SE Cab
I recently acquired a 1951 Massey Harris Pony. It was running, but the wiring was scary - cracked insulation, fraying at the terminals, etc. I bought a new harness which came with a basic "connect A to B" instruction list. I compared it to the shop manual's wiring diagram, and they match. Here's the shop diagram:

PonyManual.jpg


A previous owner had replaced the generator/light switch with a 3-position light switch. This meant having to do something with generator's F terminal (blue wire). Simple solution (though not ideal) - routed to a grounded switch. So this switch is performing lighting duty only.

My confusion lies around the starter button. I can't make sense of the diagram - it has the starter and ammeter/battery connected to the same terminal on the factory 3-position switch. Press the starter button, all you do is create a loop through the negative side of the circuit i.e. nothing happens. In order for the starter button to engage the starter solenoid, it needs to complete a circuit through ground. To me, then, that means that the factory 3-position switch must have continuity from ground to the terminal onto which the starter is connected. But if that were true, the battery would be in a constant short circuit as the ammeter/battery shows as being connected to that same terminal.

Is the shop diagram messed up? Am I? For reference (and for my own sanity) I photocopied, whited out, and re-drew the wiring diagram to correspond to the "as-bought" condition:

PonyActual.jpg
 

Tractor & Equipment Auctions

Kivel Pallet Forks (A50121)
Kivel Pallet Forks...
2001 John Deere 670C Motor Grader (RIDE AND DRIVE) (VERY NICE) (A50774)
2001 John Deere...
John Deere 3038E (A50120)
John Deere 3038E...
2016 John Deere 6130M (A50120)
2016 John Deere...
2022 Case IH Steiger 470HD AFS Connect RowTrac 4WD Tractor (A50657)
2022 Case IH...
2015 Caterpillar D6K Crawler Tractor Dozer (A50322)
2015 Caterpillar...
 
Top