Gravely 5265 short in ignition.....

[Forcarlb]

I have a gravely 5265 with a short in the ignition system. There's an inline fuse, 15 amp I think, that blows when I turn the key to the on position. I replaced the ignition switch thinking that might have been the problem, but it wasn't. I don't see any bare spots in the wiring. Does anyone know if the regulator/rectifier could cause it. It's pretty expensive, so I would like to exhaust all other possibilities before buying one. Any ideas would be appreciated.
Thanks

 

[RichardTX]

While the regulator is a possibility I would also check the stator for a short. That also can cause fuses to blow. There isn't much else left that would cause a short. Pats small engine and dbelectric have inexpensive regulators and stators.

 

[Forcarlb]

Thanks Richard, I'll check it out and let you know.

 

[Forcarlb]

It was a bare wire grounding out. Thanks again Richard

 

[RichardTX]

If a bare wire was shorting out, maybe it is time to replace the wire?

Glad to hear it was just a wire. Likely one of the cheapest faults to fix.

 

[Forcarlb]

Oh well, back to square one. Though I did find a bare wire, it's still shorting out. I never did get it started by the way. I didn't actually see any sparks from the bare wire. I just assumed that was the problem. Though it does blow the fuse every time, it will sometimes allow me enough time to check for power throughout the ignition system before it blows and I discovered that I'm not getting power to the coil. Initially I replaced the ignition switch thinking that may have been the problem, but the ignition is not OEM. I can't see where it should make a difference since it's only a 3 position switch. Frustrating to say the least.

 

[RichardTX]

Did you put a magneto ignition switch on or a switch for a coil ignition?

When you say the ignition is not OEM, what do you mean by that?

One thing that it could be is a shorted diode in the charging system.

While not shown in the wiring diagram (link below), there is a diode in series with the stator lead. The diode is buried in the stator wire loom. What I have done when I have encountered a shorted diode is to add a diode. The banded end of the diode goes to +12 volts. Radio Shack has some 2.5 or 3 amp diodes for a couple of bucks.

http://oldgravelys.net/pdf/5000_Series_IPL_0881.pdf

I suppose it could be the coil but that would be quite rare.

BTW, the ignition switch labels are wrong in the wiring diagram. There is only one "S" terminal. The other "S" terminal (light blue wire) should have been labeled "I" (Ignition).

The "R" terminal (Regulator) or white-red wire isn't even labeled.

 

[Forcarlb]

Sorry I wasn't clear. It's the ignition switch that is not OEM. I will check the diode as you suggested. But one more thing I found, is that, with the key in the on position, there is fire to BOTH sides of the ignition coil (+ and-) and no fire from the coil to the spark plug. So, I guess I should start with that. Unless you think there's something else that could cause it. As for the short that was causing my fuse to blow, I discovered that by disconnecting the wire that comes out of the flywheel housing to the coil, it doesn't blow the fuse. But as soon as I touch the coil post with that wire, the fuse blows. Is that the stator wire?
Thanks

 

[RichardTX]

The wire that coming from the flywheel housing is the stator wire. What has likely happened is the diode buried in the stator wiring has shorted. Adding a diode in series with the stator lead should fix it. If you are unfamiliar with diodes, then taking a pair of 1kv 3 amp diodes and connecting them so that the banded end is connected to +12 volts should fix that without a lot of grief. If you really want to fix it by the book, buy a new stator.

The fact that you are seeing +12 volts on both sides of the coil means that the points are open. If you were to rotate the crankshaft, you would find that at some point the "-" terminal will have 0 volts on it. This is normal.

 

[Forcarlb]

I've turned the motor over quite a bit, both by starter and by hand and both the + and - posts on the coil stay hot. I will try the diodes and let you know. Once again, I really appreciate your help in trying to get this figured out.