Battery hooked up backwards,OOP!

[cycle_gator]

Guys, EE's included, It is likely the only thing smoked is the voltage regulator and alternator diodes and any other un-protected diodes. Fuses would not blow as they will pass current in either direction with equanimity. For the same reason the fusible links should not blow either. A short circuit was not created. The two poles of the battery remain isolated, the current is simply flowing in the opposite direction.

A positive ground car goes south with the battery reversed beause the generator (most of then were) tries to become a motor as it is trying to turn in the opposite direction of its design.

Now that is not to say that in the panic of realizing his error he did not cross connect, short circuit, the battery. That would have serious consequences.

 

[biggerten]

Guys, EE's included, It is likely the only thing smoked is the voltage regulator and alternator diodes and any other un-protected diodes. Fuses would not blow as they will pass current in either direction with equanimity. For the same reason the fusible links should not blow either. A short circuit was not created. The two poles of the battery remain isolated, the current is simply flowing in the opposite direction.

A positive ground car goes south with the battery reversed beause the generator (most of then were) tries to become a motor as it is trying to turn in the opposite direction of its design.

Now that is not to say that in the panic of realizing his error he did not cross connect, short circuit, the battery. That would have serious consequences.

As another EE, I agree about the time issue, things blow very quickly. I'd be concerned about the voltage regulator/alternator. The alternator diodes would have been forward biased and conducting heavily. I'm less sanguine about reverse-bias diode protection, I'd bet there isn't any. It's common enough elsewhere, sure, but I doubt it in this application. Have been wrong before, could be wrong here, but...............

Good luck!

Huh. I thought I was typing in English.

 

[Soundguy]

Huh. I thought I was typing in English.

Yes you did... Don't worry.. the 2-3 engineers and the tech in the thread understood you perfectly.

Also as an aside.. I disagree with his notion that older vehicles with gennies suffer worse.. actually.. generators handle reverse polarity way better than alternators. I've -NEVER- lost a genny to a reverse polarity situation.. all they are is a ball of wire and brushes.. I have had some mechanical vreg breakers weld on reverse polarity, and for sure a solid state vreg replacement would go south on reverse polarity.. but the gennies themselves are pretty tough.

And as for fuses not blowing.. I've seen them blow.. sure they conduct in both directions.. but what the poster doesn't realize is when youve got current flowing reverse of the way the circuit was meant.. thet you can have some pretty high amperage.. higher that circuit design.. alt's charge at what.. 15-130a mostly... batteries discharge at what up to 400-600a? batteryies always win the arm wrestle when it comes to poor diodes...

soundguy

 

[GPintheMitten]

I've heard you can get the smoke back in sometimes, but it's pretty expensive.

Couldn't resist one more smoke joke. Sorry

 

[EE_Bota]

You EE guys are getting a little loose with some or your technical terms.

There is "smoke" and their is "Essential Electrical Ether."

If essential electrical ether escapes, the device is well and truly ruined, else the escaping ether could not really be termed "essential."

Smoke is merely a primitive analog annunciation device that engineers designed into machines that cleverly flags sections of wiring that the designer suspects may respond favorably to tuning. If you have trouble seeing where the smoke is coming from, often the machine will also have a built-in wireless inspection light that will illuminate the relevant wiring with an intensity approximately proportional to the severity of the problem. Sometimes there is even a little heater included for the cold days and the Canadians! They really thought of everything!

 

[kenstrac]

I forgot to tell him to put a pan under the tractor to catch any watts the spilled out.

 

[Soundguy]

reminds me of 'dark suckers' light bulbs that is.. they don't emit light.. they just absorb dark.. eventually they get full and don't work.. and have that telltale dark spot in them from all the dark they have absorbed...

that brings on the speed of dark. dark travels faster than light... it's easy to prove.. walk into a dark room and turn the lights on.. takes a sec before you can see everything.. now.. in that same lit room, turn the lights off.. see.. it goes dark immediatly..

soundguy

 

[BobRip]

When looking for damaged wiring, there should be some visible signs, (melted, blackened, or warped insulation.

 

[YesDeere]

Dam those leaky watts and essential smoke!!! I agree if theres smoke theres fire, find those not so pretty wires that the insulation is warped.

 

[dcyrilc]

that brings on the speed of dark. dark travels faster than light... it's easy to prove.. walk into a dark room and turn the lights on.. takes a sec before you can see everything.. now.. in that same lit room, turn the lights off.. see.. it goes dark immediatly..

soundguy

I'll have to remember that one.

 

[EE_Bota]

I forgot to tell him to put a pan under the tractor to catch any watts the spilled out.

Not only that, but if there is microprocessor control, he may even need a "bit bucket."

 

[jinman]

Sola mesa, I read your first post and noticed you said you were installing a "new battery." Have your checked that battery with a voltmeter? If it is new, there's a good chance you could put it on a charger at the correct polarity and it will take a charge and be fine.

I think you need to examine your wiring harness in close proximity to the starter for a Main Fuse. It is common to put a fuse inline that is rated at the maximum current load of your alternator. I think that main fuse is likely blown on your tractor. You may also have more damage than the fuse, but things like your lights should work even after a reverse polarity connection because lights work with switches that don't care what polarity you apply.

Your alternator is normally installed on the battery side of the main fuse, so it may be damaged, but don't assume that is the case just because it can happen.

If you can't find the main fuse, then I'd call a John Deere dealer and ask the service mananger if there is a fuse and where it is located. I don't mean to be saying those who have posted that there is no current limiter are wrong, but rather that I think the opinion of a service manager might be helpful. They may have seen a similar situation and can list the exact problems normally seen with a reversed battery.

 

[Conquistador]

My wife decided to mow with my Kubota L2050 over the summer and couldn't get it to start. I knew the battery was dying and had planned to get another over the weekend. Well, she decided to hook the jumper up to the tractor and reversed the terminals. I got a call during the middle of the day saying that she tried to start it and the battery was smoking. When I got home and checked out what she did, I realized she reversed the positive and negative, cranked the juice up on the battery charger, and tried to start it. After about three hours of trying to figure out what she had done, I found one small, well hidden, nearly impossible to get to fusible link that had burnt out. The insulation was intact, just slightly warped. How did I find the wire?? Luck I guess, I started sniffing around to see if I could smell burnt wired. I smelled what I thought was something burnt and started looking. The link insulation was just a little warped, but when I felt for the wire, it was obviously burnt in half. I cut that little section out, put in a new fuse link, and we were good to go. The tractor runs fine and the battery charger is now well hidden.

 

[Soundguy]

you got lucky.. bat chargers are current limited devices, with respect to loads like starters.. etc... even heavy diodes in the alternator.

a battery is another beast.. can get some high surge current for a decent amount of time out of them in a reverse current situation.

soundguy

 

[Scotty370]

Now, if someone could just develop 'schrader' valves, for the expensive components,..........and 'canned-smoke'........... HMMM! ~S

 

[Soundguy]

not a schrader valve with can of smoke.. but as it has bene mentioned.. it is feindishly easy to incorporate reverse current protection to all sensitive electronics that are low to medium current, and even to charge output devices like alternators... just requires a small handfull of common components.. thus more cost and complexity... think of that as a 'relief' valve'..

soundguy

 

[sola mesa]

Hey guys, thanks for all the help. So far I have replaced the alternator ( old one was checked and bad), voltage regulator and ignition. I still do not have anything happening when I turn the key. Still no lights either. The tractor will try to start when I hot wire the starter.
I will make that call to John Deere about the main fuse and I will keep looking for wires that may be fried.
Any other suggestions appreciated!

 

[sola mesa]

Thanks good thoughts.

 

[Soundguy]

check all fuses plus the wire feeding the panel itself.

some machines use a relay in there as well.

soundguy

 

[kenstrac]

Hey guys, thanks for all the help. So far I have replaced the alternator ( old one was checked and bad), voltage regulator and ignition. I still do not have anything happening when I turn the key. Still no lights either. The tractor will try to start when I hot wire the starter.
I will make that call to John Deere about the main fuse and I will keep looking for wires that may be fried.
Any other suggestions appreciated!

Since you have power to the starter we can assume that the 12V is getting there and you have a good ground,Get a analog meter or test light find white wire on Alt connected to A see if you have 12V go to white wire on voltage reg,and see if you have 12V go to white wire on key sw marked B see if you have 12V if not on any of these the wire is open-burnt .
The wire originates from the large term. on the starter that the bat.is connected to check that Stak-on.
all these white wires are spliced inside the wiring harness and you will have to cut open the harness to find the junction where I suspect your problem is .
Hope this helps.
BTW disconnect Bat before cutting into harness