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Discussion Starter · #1 ·
I bought my first Deere, a 77 or 78 2040 Tuesday. Today after washing it, I had an electrical short in the wires going to the dash lights. After removing the burnt ones, my headlights, water temp gauge still work and it still fires up and runs. Problem is the alternator no longer charges but Ive only had it a couple days so Im not sure if it charged before or not. It has a reman alternator on it. Im thinking its a newer style. Where should I start? Have it checked at a parts store? Tractor came with a couple repair manuals but there is no schematic in either of them. Will a Chevy 1 wire alternator work?
 

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Welcome to GTT
Wiring on JD 2040 is very simple compared to tractors built today. Voltage regulator(key 15) is located under dash. Yes one can adapt a Delco type alternator to fit & charge on a 2040
 

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By dash lights, do mean dash warning lights?
How did you determine it's not charging? Is your ALT light staying ON?
By "newer style" alternator, do mean not wired the same as original?
 

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Discussion Starter · #4 ·
Mine has a newer John Deere reman with regular built in. I wonder if it needs to see something from the idiot light for it to properly charge?
 

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Discussion Starter · #5 ·
There was a short in the dash lights yesterday. Charging, oil pressure and whatever the other one does. The red wire going to them burnt. The previous owner says that’s why it isn’t charging. That it needs a signal from the light for it to charge. Anyone have a schematic of the dash light with the wiring colors labeled? The original alternator was replaced by one with a built in regulator.
 

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From A (accessory) terminal of Key switch, purple wire to connectors for ALT and OIL warnings lights. At these connectors, the purple wires changes to orange wire for ALT, and black wire for OIL lights. Then from ALT light, two orange wires, one to alternator and the other to the voltage regulator. From the OIL light, a black wire to the oil pressure switch on the engine.
 
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