# Short circuit



## robere (May 11, 2018)

Hello all. Name is Bob and I am NOT a mechanic. I know nothing about it. So that being said. I have a 1966 Sears Suburban. Between me,my brother and bro n law, we got it running good. I was using it the other day and it began running bad. It finally died and the negative battery cable was very hot. I'd turn the ignition key and smoke immediately came off the negative terminal. I've obviously got a short somewhere. Any ideas on how to track it down? 
I love this little tractor. Powerful little machine. Thank you.


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## RC Wells (Dec 26, 2008)

The Sears Suburban (David Bradley) uses a starter/generator. If the key switch or voltage regulator fails it will attempt to activate the starter and generator functions simultaneously. Creates a dead draw on the battery. Since you can shut the key off and the draw stops, I would suspect the regulator, or a short in the load side brush holder in the starter/generator.

Disconnect the wire #36 in the diagram on page 10 of the attached parts manual and see if the draw quits. If it does stop the draw, leave the key off and take your multimeter, set it to ohms and measure from the corresponding voltage regulator terminal to the ground (engine block) (A free Harbor Freight multimeter works just fine for this). If it is infinity the problem is in the regulator. If that is less than infinity, check the corresponding starter/generator terminal to ground. If it is infinity it will likely be a failed brush holder in that unit. I attached the parts manual so you can take a look at the wiring diagram.

If you need parts, here is a reference site: http://isavetractors.com/electrical/starter-generator-parts/


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## robere (May 11, 2018)

Thank you so much. I'll see if I can do this. I've got a good meter. I'll post the results.


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## Bill Kapaun (May 8, 2007)

Clean the connections on the ground cable.
Inspect for broken strands that could be hidden under the insulation near the battery end.
Often acid fumes get under the insulation near the cable terminal and eat away unseen.
The hot spot will be where the resistance is.

I think you'll find the problem there, since the positive cable isn't getting hot and it'd be carrying the same Amps.


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## robere (May 11, 2018)

Bill Kapaun said:


> Clean the connections on the ground cable.
> Inspect for broken strands that could be hidden under the insulation near the battery end.
> Often acid fumes get under the insulation near the cable terminal and eat away unseen.
> The hot spot will be where the resistance is.
> ...


So I tried this 1st since it seemed the easiest. It was actually the positive cable that got hot,not the negative. I replaced it and Boom. Started right up. Thanks.. So now, I rode it around for about 10 minutes and it died. It cranks,where it didn't before,so it's something else. Could be the carburetor or the fuel pump I assume. Is it easy to rebuild the carb on this or should I replace it? It's been kinda funny on the way it runs since I've had it. Just not real consistent.


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