Weekend Freedom Machines banner
1 - 4 of 4 Posts

· Registered
462 Posts
Discussion Starter · #1 ·
I got my 430 put all back together today. I've had a lot apart, so I'm not sure what would have happened, but the battery light is on all the time now. It is nearly a new battery. Starts tractor fine. I measured voltage with tractor off at 13. Measured voltage with tractor idling at 14.3. So the voltages seem fine. Any thoughts on what to check? Looks like the controller is in the time delay module. I didn't have this off. Had the firewall loose to get out the driveshaft though.

· Premium Member
10,382 Posts

The battery charge voltage lamp on the 430 is only driven by the TDCM for some early tractors, but in others by the voltage regulator module itself. Here is the theory of operation description from the manual:
For (S.N. —420468):
Battery discharge lamp (P3) warns the operator when
battery voltage is low (battery voltage below
specification). The battery discharge lamp DOES NOT
monitor current output from the alternator.
Battery discharge lamp controller (B) senses battery
voltage present at fuse (F2). If the lamp controller
senses low voltage (less than 12.3 volts), the lamp
controller provides a path to ground for the battery
discharge lamp. Since battery voltage is always
available at the discharge lamp when the key switch
is at the RUN position, the ground path provided by
the lamp controller will allow battery current from fuse
(F2) to flow through the battery discharge lamp and
lamp controller, causing the discharge lamp to turn
on. The discharge lamp will stay on until battery
voltage increases to approximately 12.7 volts. At this
point, the lamp controller will break the path to
ground, turning the discharge lamp off.
For (S.N. 420469— ):
Battery discharge lamp (P3) warns the operator when
alternator output is low. It DOES NOT monitor battery
state of charge.
When the engine is not operating and the key switch
is in the RUN position, the regulator senses no
current output from the alternator. In this state, the
regulator provides a path to ground for the battery
discharge lamp, turning the lamp on. During engine
operation, the regulator will also provide a path to
ground for the battery discharge lamp when current
output is below specification (less than 12.3 volts).
When the engine is operating and the alternator
produces current output that’s over the minimum
specification (approximately 12.7 volts), the regulator
senses the current output and breaks the ground path
to the discharge lamp, turning the lamp off.
Note there are separate descriptions for the various serial number ranges... What is the SN of your machine?

Here is the wiring diagram:
Font Schematic Line Rectangle Parallel


· Registered
5,072 Posts
might just be corroded battery terminals that will make it look discharged and boil the battery trying to charge it

· Registered
1,849 Posts
Also check belt tension for the generator/alternator. Check the TDCM plugs/terminals for corrosion/dirt after decades of exposure to atmosphere (moisture/temp swings, dirt from the radiator fan blowing back into the pedestal)
1 - 4 of 4 Posts