Wiring my engine from the key.

michaelneff22

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I've been having problems with my mower lately, not starting from the key so I rewired it using my steps below.

5 prongs on the ignition switch- SBLMG

S- post on starter solenoid
B- Wire straight to the battery with a 20 amp fuse
L- Red Stator Wire and Grey Wire from Carb
M- Black Wire from Coil/ Magneto
G- Ground

Mower starts and Run fine using my steps above. But the "B" Wire Straight to the battery and 20 amp fuse was very hot and then melted at the fuse. My Question is WHY?
 

ILENGINE

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Depending on the charging system output that could put a good load through the keyswitch, which it may not be intended to handle. Everything looks good but I would move the wire from the stator directly to the battery and not go through the key switch. The diode or regulator will prevent battery discharge if it is working properly.
 

bertsmobile1

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With that switch the output from the alternator should be going to the hot wire on the starter solenoid.
When I do a rewire I fit a fuse to that wire rated to the output of the alternator so if I get a dead short. it will blow.
 

michaelneff22

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So before either of you guys wrote back I just hooked the wires back together after they melted off the fuse area and mowed my grass and touched the wire a few times while mowing everything seemed fine.

But I'll defiantly run the Red Stator wire to the battery if that is what your saying I should do.

Thanks
 

michaelneff22

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Oh and the B wire that burnt up the mower wasn't running.
 

bertsmobile1

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The B terminal is to supply power to the starter switch so that the starter switch can energise the fuel solenoid and the starter solenoid and the PTP switch if it has an electric PTO.
It should never have a feed from the alternator fitted to it.
Some older mowere have extra terminals to isolate the stator when the engine is turned off to prevent back feed trying to run the alternator as an electric motor.
Some Kohlers has a pair of wires fro the stator which the ignition switch shorted out when you shut down the engine to stop it faster this was an early attempt to meet EPA regulations which the fuel solenoid now does.
The usual wiring runs the output directly to the battery side of the starter solenoid, simply to save wire and reduce clutter at the battery terminals which are more prone to corrosion the more terminals that are connected.
Again for simplicity & economy with wire the power feed to the ignition switch is generally taken from the starter solenoid hot wire as well and that wire is generally fused.
I like to fit a slow blow fuse to the alternator output wire as well rated at the maximim output which should only happen for a short while after starting.
If any wire melts with the mower tuned off then you have either a bad switch or a short to earth some where.
 

bertsmobile1

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The B terminal is to supply power to the starter switch so that the starter switch can energise the fuel solenoid and the starter solenoid and the PTO switch if it has an electric PTO.
It should never have a feed from the alternator fitted to it.
Some older mowere have extra terminals to isolate the stator when the engine is turned off to prevent back feed trying to run the alternator as an electric motor.
Some Kohlers has a pair of wires fro the stator which the ignition switch shorted out when you shut down the engine to stop it faster this was an early attempt to meet EPA regulations which the fuel solenoid now does.
The usual wiring runs the output directly to the battery side of the starter solenoid, simply to save wire and reduce clutter at the battery terminals which are more prone to corrosion the more terminals that are connected.
Again for simplicity & economy with wire the power feed to the ignition switch is generally taken from the starter solenoid hot wire as well and that wire is generally fused.
I like to fit a slow blow fuse to the alternator output wire as well rated at the maximim output which should only happen for a short while after starting.
If any wire melts with the mower tuned off then you have either a bad switch or a short to earth some where.
 

cashman

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On Kohler CH and CV engines the circuits that powered the carb fuel solenoid and spark advanced module (if equipped)
were diode protected.
 
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