iDRY Vacuum Kilns

Sponsors:

Hooked up backwards jump start

Started by Qweaver, July 28, 2015, 06:08:43 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Qweaver

Stupid, Stupid, Stupid.  Went out to saw this am.  Dead battery because I left it switched on.  Danged if I didn't hook it up backwards.  How dumb can I get.  Replaced the 40a fuse and I can now start with a proper jump and it will run fine on the jumper battery but quits shortly after I un-hook.  So I've burned out the charging system.  What do I need to replace?  The saw is an LT28 with the B&D 25.  Just did not have my brain switched on this AM.   :'(
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

POSTON WIDEHEAD

Have you tried a new battery yet for starters? (no pun intended )
The older I get I wish my body could Re-Gen.

Qweaver

Quote from: POSTONLT40HD on July 28, 2015, 06:38:16 PM
Have you tried a new battery yet for starters? (no pun intended )

I'm going to unhook the battery and hookup another one that I know is good, start the engine and see if it will charge.  It was so hot today that I just did not want to work on it.  It's still 90 out there.  I'll give it another hour to cool off some.  I guess these small engines should still show @ 14v when charging?
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

sawguy21

 Charge the battery as normal and start the engine, you should get 14.5 vdc at full rpm. If not the smoke got out of the regulator.
old age and treachery will always overcome youth and enthusiasm

r.man

The good news is that the battery did not blow up. I have not seen a set of polarity free cables but I know they exist. http://www.autoblog.com/2010/03/20/never-blow-up-your-battery-with-michelin-smart-jumper-cables/
Life is too short or my list is too long, not sure which. Dec 2014

red

I paint my battery's Half RED to prevent this 
Honor the Fallen Thank the Living

Seaman

The batt is probably so dead it will not run the ignition. I doubt you hurt the charging system. I think if you take the batt out and fully charge it you will be back in business. I hope so anyway!
FRank
Lucas dedicated slabber
Woodmizer LT40HD
John Deere 5310 W/ FEL
Semper Fi

John Mc

You may have damaged the battery enough that it will not hold a charge. You can try charging it - the less time it sits discharged, the less problem you'll have with sulfation. A charger with a desulfation feature may help bring it back, but not if one or more of the cells is shorted out.

The plan of trying the system with a known good battery is a good one. Most likely, all you have damaged is the fuse and the battery. That fuse is supposed to protect your charging system.

John
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Qweaver

I removed the dead battery and jump started the saw.  The battery showed  12 v before starting and 12 v running at sawing speed.  The saw would die if I unhooked the battery and continue running when I hooked it back up.  So I am not making any electric. :'(  I know little about small engine charging systems.  I guess I need to get a book and study up on them.  What do I need to change first?  I have a lot of sawing to do and this is a nuisance.  (of my own making)
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

Ford_man

You may have reversed the polarity of the alt which will discharge the bat to the point it will not run. so if it runs with a charged bat run it to see if it keep running more than an hour if not you can reverse the polarity again and it may charge. I done that same thing an a car one time it would run for about 20 miles and dye.

Qweaver

How do I check and reverse the polarity?
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

sawguy21

I very much doubt you hurt the alternator, the diodes in the voltage regulator are likely popped. However, the v/r may be incorporated into the alternator, I assume yours is belt drive, which means replacing or having a shop repair the unit.
old age and treachery will always overcome youth and enthusiasm

Lazy logger

You can check the output of the stator/alt for voltage with your meter. Check it before it gets to the reg. it is A/C, You should be able to get the specs online or someone here may know. If that's good then you have most likely popped your reg. which in my experience is probably it.
I know the voices in my head aren't real,but sometimes their ideas are just absolutely awesome!

Qweaver

This engine is a Kohler 25 pro on a WM LT28.  Is the alternator not built right into the flywheel?  I may just download a manual.  I have much experience with car engines and practically non with small engines.   
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

Lazy logger

Yes, That makes it a stator. The magnets in the flywheel spin around 1 or more coils of wire mounted the the engine. It produces AC voltage up to (I'm Guessing) 50-60 volts at cranking speed. This AC voltage gets turned into DC in the regulator/rectifier. Then goes to the batt. to charge it. The rectifier portion has the diodes that do not like reverse polarity.
Hope this helps.
I know the voices in my head aren't real,but sometimes their ideas are just absolutely awesome!

John Mc

Not knowing your exact Model number, it's hard to give a good description. The Kohlers I've seen in that size range have two wires coming out of the engine from the stator. Follow these two wires to where they plug into a little box. This is the voltage regulator there should be three wires coming in to the VR (two from the stator carrying AC voltage, and one output carrying DC voltage - I believe the DC wire is purple on some Kohler engines in this size range).  NOTE: if the wires each have separate connectors, make sure you mark which wire goes where before disconnecting

If you disconnect the wires to the regulator, making sure none of them can accidentally connect to ground. Measure the AC voltage between the two stator wires with the engine running at about 3600 RPM under no load (generally, full throttle). The voltage should be 28 VAC or greater (at least on the model Kohler I have) if it's not, you likely have a bad stator, and it will need to be replaced.

You can also check the resistance of the stator with an ohmmeter if you want. It should be about 0.1 or 0.2 ohms between the two leads with the engine off and leads disconnected from regulator. If it reads infinite, the stator is open if it reads 0 ohms the stator is shorted. NOTE: some ohmmeters will not read accurately down as low as 0.1 or 0.2 ohms - even some good ones are just not designed to read this low, so don't automatically panic if you get a zero reading. If you are getting 28+ VAC when running, it's NOT shorted and it's NOT open. I believe each lead should also read infinite resistance from ground - at least it does on every Kohler I've ever checked (which admittedly is not a lot).

If your stator is good, it's probably your regulator. With the appropriate AC input, the output wire of the regulator should be reading 13.8 or more between it and ground when properly connected to a known good and fully charged battery (I would take your questionably battery completely out of the circuit when doing this test, rather than just jumping it with another battery). If all your connections are good, you can just measure this at the battery terminals, rather than at the regulator DC output wire.

A new regulator costs about $50 at Jacks Small Engines. They have a pretty good engine parts locator system, but you will most likely need to have your engine model number.

If you know your model number, you can download a service manual for most Kohler engines for free here: http://www.kohlerengines.com/manuals/landing.htm.  It will give you more specific guidance for your particular engine. The manual may describe how to test a regulator using a special testing device, but that is generally not necessary: if you know you have good output from the stator wires, your wiring and connections are good, and you are connected to a known good battery, it's fairly easy to determine if the regulator is working or not. If it can maintain 13.8 volts, even with an electrical load (try hooking up a load - maybe a couple of 12 volt lights or a cigarette-lighter powered air compressor to it whiie the engine is running and see what the voltage does.)
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Qweaver

Thanks for that reply John.  I charged the battery overnight and it held the charge well.  I hooked it back up and sawed 2 12"x 8' logs down to 7" posts and re-sawed and edged two thick slabs to 2" boards and still had 12+v in the battery.  But I was still not getting charging voltage from the engine.  I think the regulator can be changed from outside of the engine without removing the metal covers.  I saw a $28 regular on Amazon.  I just need to make sure it is the right one.  I'm amazed that the battery was able to run the saw for as long as it did without any voltage drop.  I did not measure it under load however.  I'll try and order a regulator today, if I can be sure that I've located the right one.
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

John Mc

If you are not running any electrical accessories, there is no reason the battery would discharge much while the engine is running. Cranking the starter would bring it down a bit, but if you didn't have to do a lot of cranking to start it, it wouldn't drain it much?

If you are only showing 12 V at the battery while the engine is running at speed, you have a problem.

The regulator is usually mounted on the outside of the engine and shroud. On the vertical shaft 25 HP Kohler pro on my lawnmower, the regulator is a little gray 1.5" X 3" box held to the side of the cooling shroud on by two bolts. It has two white wires and a purple one coming out of the connector on it. You may also see a grounding wire or strap attached to one of the mounting bolts. Very easy to get to and replace.

Make sure you get the right regulator for your engine. They come in different amperage ratings. You want one with at least as high a rating as what is on there now.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Qweaver

The battery does a lot of work on this saw.  It powers the motor that drives the carriage up and down the frame.  The starter motor also pulls a fair few amps.
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

John Mc

I forgot about all that battery related stuff (can you tell I'm not a sawyer?)

FYI - 12 V is partially discharged for a "12 V" battery. For a flooded lead acid battery (e.g. typical car battery), if you charge it fully and then let it "rest" for at least 12 hours with no further charging or load on it, it should still read close to 13.0 volts. If it's only reading 12 volts after a full charging, you've got a battery problem. It may be as simple as topping off the water in the battery cells. If it's sulfated, you may be able to desulfate it with a battery charger that has a desulfation circuit. If it's got a bad cell, it's time to junk that battery.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Qweaver

The reading was actually closer to 13.5v. We just refer to the system as a 12 volt. The fact that it ran the saw for as long as it did makes me think that the battery is fine.  I'll locate the proper regulator tomorrow and I think I'll be back in business.
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

Claybraker

Quote from: r.man on July 29, 2015, 07:29:39 AM
The good news is that the battery did not blow up. I have not seen a set of polarity free cables but I know they exist. http://www.autoblog.com/2010/03/20/never-blow-up-your-battery-with-michelin-smart-jumper-cables/

I picked up an InstaBoost from Lowe's a few months ago. It's got all the electronical protections- polarity, overload, etc. and enough oomph to jumpstart most engines. Real handy for toys that don't get used often. Much easier than dragging out jumper cables.

Qweaver

I ordered a new reg/rectifier today.  $24 bucks with free shipping.  Cheap enough to undo an act of stupidity.
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

Qweaver

My LT 28 engine is still not making charging voltage.
I received the new regulator yesterday.  Plugged it in, started the engine and no charge.  In fact the voltage was lower.  I was careful to hook up the wires exactly as they came apart and I called the supplier to be sure I was ordering the correct part.  I noted that there was a spark when I connected the regulator and I thought at the time that that should not have been so...but the only connections are two ACs in and a DC out to the battery.  I assume that these are a full wave bridge rectifier, so polarity should not matter.  These are such a simple charging system that I hate idea of unbolting the engine and taking it to a local shop.  Where do I go next? 
So Many Toys...So Little Time  WM LT28 , 15 trailers, Case 450 Dozer, John Deere 110 TLB, Peterson WPF 10",  AIM Grapple, Kubota 2501 :D

John Mc

Should not be a spark if the engine is not running, unless you've got a short in some other wiring.

Did you ever check the stator wiring? the resistance between those two leads (when disconnected from the regulator) should be on the order of 0.1 or 0.2 volts  - NOTE: a lot of voltmeters will not accurately measure resistances this low. The resistance between either of the leads to ground should be infinite.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Thank You Sponsors!