Craftsman GT18 Electrical help needed

Got diode partially made and went out to check. Looked like I was getting +5/-5. I took it apart and back to work table and that's when I find out molex connector won't fit in lights side of connector. Looks like the lights is a smaller size.

I'm beyond frustrated at this point. I didn't want to buy a load of connectors for just 3 so I spent WAY too much time pulling apart computer molex connectors for their pins.

I'm going to do what I didn't want, but I'm going to cut connectors and make my own harness of sorts.
20190421_211156.jpg
 
Yup, I'm an idiot. Just had a moment of clarity...the computer molex connectors have the male and female side. I think I might have used wrong side.

Regardless it might be easier to make my own harness. My unfortunate goal is to sell this tractor even though I like it.
 
So, I had some more clarity. I just pulled two male connectors with wires from the computer power supply and used a heat shrink with solder and connected them that way to the diodes. it's a little longer than the original, but should do the same. The original end connector was melted, so I had to hot glue one connector in.

Yeah, I hate to sell it. I just love the sound of that dual muffler. And it looks like a tractor. But, I can't have 5 in the barn. I have a JD355 Diesel coming and need to get rid of a few before it shows. I have a JD317 that I have the plow, blower, and deck for, a Simplicity that I use for mowing, and then the two Craftsman. One, the GT6000, I don't mind parting with. This one is hard. BUT....we'll see :)

oh, and that harbor freight shrink wrap sucks.

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Ok. Just hooked up my connector while wife fed baby. I only hooked up side from alternator. I was getting, at full throttle, about 1.0 +/-

So I then unplugged and only hooked to switch. With key off it didn't register anything, but with key on I was getting voltage back through diode, is this wrong? I thought diode only let voltage one way, maybe I'm wrong.

20190422_193434.jpg key off, engine off
20190422_193421.jpg Key on, engine off
 
With key off and engine not running you shouldn't get anything. Cross fingers, hook everything up, and measure across the battery. 12.something not running. Crank the engine and it should start slowly rising to 13.something. Depending on the diodes, there may be some low voltage leakage, not an issue with the key off.
 
On the side of the diode that goes to the switch OK. On the side of the diode that goes to the stater ..... Wait there is the light diode in play now so this gets complicated. It's late I'll make some in circuit measurements tomorrow evening.

I am thinking (without testing) this is a correct reading. The switch disconnects both diodes. You may want to check for a short in the light circuit now.
 
Could your diode(s) still be reversed?
 

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Can you measure the diode out of circuit? On OHMS it will read "open" one way, and reversing the leads should show around 0.5 OHMS.

Also Try omitting the Light diode and just use the charge diode and to the test you did above again (If you still get 12V try reversing the diode).

You definitely have a strange one, Issue that is.
 
Yes, wrong Diode type for this application. you need a standard 6 - 10 amp power P-N diode.

Schottky diode

The Schottky diode (named after German physicist Walter H. Schottky), also known as hot carrier diode, is a semiconductor diode with a low forward voltage drop and a very fast switching action. The cat's-whisker detectors used in the early days of wireless and metal rectifiers used in early power applications can be considered primitive Schottky diodes.

P-N Power Diode

A p-n junction diode is two-terminal or two-electrode semiconductor device, which allows the electric current in only one direction while blocks the electric current in opposite or reverse direction. If the diode is forward biased, it allows the electric current flow.
 
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