Newbie question for starter solenoid on Deere L120A

9 years ago

Before I get lots of haters let me say I did well putting it this old L120a with a swapped out motor together from several boxes of parts and manuals so forgive the stupid question. I don't read electrical schematics well.

Question: does it matter which side the switch wire (purple) goes to? Should it, or does it have to be, on the same side as the cable to POS battery post?

Starts fine, runs okay. Battery will not charge. Tested stator output (48 Amps). Tested regulator for correct resistance. Are in the range of the manual.

Mower: Deere L120A
Engine: B&S 422707-1214-01 (repowered obviously)

Comments (11)

mla2ofus
9 years ago
Makes no difference which way you connect them. The purple wire carries voltage to the solenoid and the black wires complete the circuit to ground via the safety switches. All they do is close the solenoid contacts to the starter to energize it.
I believe you're stator test was reading AC volts instead of DC amps. With the engine stopped check DC volts at the batt, should be a little over 12v. Start the engine and at full throttle check again, should be 14 - 15v. If not you have a voltage regulator, fuse, ignition switch or wiring problem.
Mike
Maranda519
Original Author
9 years ago
Cool. Thanks. That's what i was thinking given the mechanics of the solenoid but one never knows. Batt is 12.9v. Not checked at full throttle but will. Thanks again.
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mla2ofus
9 years ago
Glad to help and hope it is an easy fix.
Mike
Maranda519
Original Author
9 years ago
Checked battery
Off: 12.9V
Full throttle: 13.2

Wiring, regulator, and abttery are new. Darn!
Multi-meter won't go to 30 so hard to test regulator.
Will start by running resistance across wires back to fuse and connector.
mownie
9 years ago
***"Multi-meter won't go to 30 so hard to test regulator."***
30? 30 of WHAT? Volts, amps, ohms?
Maranda519
Original Author
9 years ago
Amps ... 30 amps.
Maranda519
Original Author
9 years ago
Wait ... was reading the manual wrong. Was looking at the worng charging system. Mine should be 2-3 Amps, not 30. Yikes.
mownie
9 years ago
That is why I questioned what you were trying to measure :^)
bill_kapaun
9 years ago
Several things you posted make me wonder-
What's the ACTUAL model of the tractor?
I See an L 120 and an LA 120, but no L 120A.

Which manual were you reading that states 3 Amps? The one for the tractor or the one from the repower engine?
They "could" have VERY different charging systems.
That can lead to "issues" if you don't know how to work around that.
mownie
9 years ago
I wondered about how you referred to "testing the REGULATOR", and now you come back and state that the engine has a 3 amp charging system.
If in fact the engine has a 3 amp charging system, there will be no regulator included with it.
The Briggs 3 amp charging system is a simple, diode rectified, non regulated charging system.
In essence this means that the max amp (and voltage) output is
only going to occur at max RPM (or near max RPM).
So, is there an actual voltage regulator included in the configuration? If so, was it part of the original engine or part of the replacement engine?
If the Deere has an electric PTO clutch and the replacement engine only has a 3 amp charging system, you will not have enough alternator to keep pace with the PTO drain on the electrical system.
Maranda519
Original Author
9 years ago
Model L120A (GXL120A 080231)
Repowered with B&S 18HP 422707-1214-01
16 Amp charging system
Regulator: Yes. Two yellow, one red.

Relooked instruction in B&S Regualtor manual and 422707 manual. I think I might have been looking under the dual-circuit charging system before.

Tested stator output and voltage at battery.
Stator pushing 48 VAC at full throttle.
Battery voltage before start (12.39DCV)
Battery voltage immediately after start (12.29DCV)
Battery voltage after 15-20 minute full-load (PTO on, blades cutting) hot-wash (13.4DCV)

Determined issue most likely was me.
Numerous quick on/off cycles to diagnose and fix fuel and carb issue lead me faulty conclusion regualtor was faulty when, in fact, I wasn't giving the system time to regenerate.

Time to run it and see what breaks.

Thanks for the assist(s) and patience.