Uh Oh...What did I fry?

F7Hooligan · #1 04-29-2010, 05:57 PM

I was going to jump start my truck with my 149 so I could move it to mow the lawn, (the battery in the truck went South a couple of days ago). As soon as Hooked the cables up, the charge indicator went to max. Tried to start the truck and the tractor stalled just as if the key had been shut off. Pulled the plug and no sparky.

Any guesses as to what I fried? As I'm typing this I'm thinking maybe there's a fuse on the voltage regulator? Any one care to take a guess whilst I go back out and have a look see?

F7Hooligan · #2 04-30-2010, 07:56 PM

Well, according to my manual I don't have any fuses. I checked the coil and it reads identical to the one on my other 149. It also meets the specs listed in the coil test on this site. When I turn the key switch on I have 12.4 volts at the coild (drops to 10V) when the starter engages. Still no spark. I thought maybe the points were stuck open so I pulled the cover and the contact is opening and closing as it should.

It seems the only thing left is the condensor. If that failed would it cause a no spark condition? I thought it was there to absorb the collapsing coil field...any thoughts before I try swapping parts? I like to have it narrowed down first, I hate the shotgun method.

R Bedell · #3 04-30-2010, 08:23 PM

Try charging the Battery of the 149 up to a full charge.

F7Hooligan · #4 04-30-2010, 08:41 PM

I know the voltage sounds a little low but it spins the starter-generator w/no problem so I ruled that out. I might as well give 'er a try. I'll charge it up tonight and see how she fares in the AM.

Rhoderman · #5 04-30-2010, 10:23 PM

Turn the engine over by hand until the points are open.

Hook an old spark plug to the plug wire and lay it on the head.

Turn on the key and momentarily tick across the points with a screwdriver. Short across the body of the points, not the points themselves necessarily.

If you see spark, everything should be okay.

Sounds to me like when you hit the starter on your truck, you pulled the voltage in the cub battery down to almost nothing, which would kill the engine.

I hope it's simple and easy. It does seem odd that you can roll the starter and not get it to fire.

When your ammeter pegged, it was showing that all the current from the generator was going to the truck battery.

Hmmmm... Maybe you smoked your ammeter? That doesn't feed the starter, but it DOES feed the coil.

R Bedell · #6 05-01-2010, 07:06 AM

FYI....The Charging System on a Cub Cadet is only 15A at a maximum.

When you start up a truck as you described, that starter uses in the neighborhood of about 75A. Like Rhoderman said, you pegged the Amp Meter and could easily depleted the battery charge to the point of not having enough to feed the ignition coil on the Cub.

Rhoderman · #7 05-01-2010, 11:15 AM

I took a look at the wiring diagram for a 1x9. If your ammeter was killed, you wouldn't be able to roll the starter from the key switch. So that probably isn't it.

Probably a battery too low, but that coil should work down to some very low voltages I'd think.

Good luck with it, and post what you find!

F7Hooligan · #8 05-01-2010, 02:42 PM

Allright, here's what I found. I actually had some time to take a good look at the problem today without being interrupted so here's what I did. I pulled my other 149 out and started from scratch comparing continuity readings between the two. I found that even with the points closed I couldn't read from the negative side of the coil to the frame of the tractor. Pulled the cover off and yep, they were opening and closing as they should but I had very high resistance across the contacts. Cleaned them up and she fired right up.

I'm guessing that when I tried jump starting the truck I dropped the voltage enough that it caused the points to "burn".

Bottom line is...don't try jump starting your truck with your Cub Cadet.

Thanks for all the help guys, time to mow the lawn...