Please help with 854 electrical

[WheelHorse79 271]

Hello everyone.

 

My 854 started and ran fine before I restored it.  Last Sunday, I started putting the wiring back on the tractor.  I checked the continuity of all the cables.  I made a new coil wire and also checked it.  I wired everything up according to the 854 manual's wiring diagram, onto an NOS key switch.  I put the battery back in and turned the key to start.  Nothing happened, but the key switch became very hot and the negative ground cable began to smoke a little where it attaches to the engine ground.  I put in a new battery and wired up my old key switch, and the same thing happened again.

 

Any suggestions on what might be wrong?  Is there any way to "jump" the starter/generator to see if it will turn over the engine?  BTW: I can turn the engine over freely by hand.

 

Thanks in advance for your responses!

 

 

[buckrancher 2,675]

some pictures of the wiring would be a great help

[Jeff-C175 7,195]

Could you have possibly reversed the connections on the starter/generator?  The wire from the switch to the generator output instead of the start terminal? 

 

I don't know that this would do it, but the first thing I would check is that the wiring was correct, and there certainly isn't a lot of it on that machine!

Edited August 21, 2013 by Jeffpicks

[WheelHorse79 271]

Here are the best pictures I could get:

 

:

 

 

[Jeff-C175 7,195]

Schematic only shows one wire from the start terminal on the switch to the s/g lug.  What's that other wire on the s/g with the heavy black one?

[WheelHorse79 271]

Looking at the starter switch, the large black wire is going to the S/G.  The large red wire is the positive batter cable.  The smaller wire coming out of the positive cable goes to the ammeter plus.  The smaller red (pink) wire goes to the coil + wire.  The wire on the middle terminal of the regulator goes to the ammeter minus.  Thanks again for looking at this.

[Jeff-C175 7,195]

That all sounds right, but on the S/G along with the black cable to the ignition switch there is another wire... or at least it looks like there is?  Where does that one go?

[rmaynard 14,915]

Is there any way to "jump" the starter/generator to see if it will turn over the engine?  BTW: I can turn the engine over freely by hand.

 

 

Yes. First, make sure the transmission is in neutral. Take your jumper cables and connect the battery ground (black) to the engine/frame, then touch the hot (red) to the lug on the S/G. It should turn over.

 

Wiring looks good in the pictures. Only thing missing is the battery. I am assuming that the small red wire connected to the 6 gauge wire at the ignition switch is going to the ammeter.

 

Edited August 21, 2013 by rmaynard

[WheelHorse79 271]

On the S/G, the left terminal goes to the nearest terminal of the regulator.  The right terminal of the S/G has the large black cable going to the starter switch, the smaller wire goes to a terminal underneath the middle of the regulator.  The middle terminal of the regulator has a wire going to ammeter minus.  I hope this helps.

[Jeff-C175 7,195]

I've circled the wire:

 

[Martin 2,130]

that wire goes to the 4th terminal under the regulator

[Jeff-C175 7,195]

 

large black cable going to the starter switch, the smaller wire goes to a terminal underneath the middle of the regulator.

 

Posts crossed in the mail...

 

I don't see that wire on the schematic... I can read schematics but I don't  know your machine...

 

Bob, what is that extra wire, do you know?

[Jeff-C175 7,195]

Thanks Martin... wonder why not shown on diagram?

[rmaynard 14,915]

It's not on the WH diagram, but it is in the Kohler manual.  It's called the generator armature terminal.

 

Edited August 21, 2013 by rmaynard

[Jeff-C175 7,195]

What if that wire were lifted for a test... just leave the black from the switch in place..?  (in order to isolate the regulator as a possible source of the problem)

Edited August 21, 2013 by Jeffpicks

[WheelHorse79 271]

Thanks everyone.  I'll try the "jump" test tomorrow night when I get home from work.  And, I'll remove the wire going from the S/G terminal to the terminal under the regulator during the test.  If it works, then I must have a bad ground or a bad wire somewhere. I did make sure not to paint the surface where the S/G mounts to the engine block, so I should have a good ground.    I'll have to drag out the volt meter again. 

Edited August 21, 2013 by WheelHorse79

[Save Old Iron 1,563]

If your smoking a 6 gauge wire your problem is not poor grounds but either a shorted Starter Generator or a short in the wiring lead out of the ignition switch.

 

To test the SG, first disconnect the large cable to the SG "A" terminal. Use car jumper cables to connect the battery to the SG. Positive battery cable to SG "A" terminal and the negative battery to the engine ground. The SG should turn over nicely without any excessive current draw or smoking the battery cables. Regardless of if the engine and SG turn over by hand, the SG could still be shorted internally. If the SG does not turn over nicely when connected thru jumper cables (or if the jumper cables start to get warm), stop the test and investigate the SG. 

[buckrancher 2,675]

If your smoking a 6 gauge wire your problem is not poor grounds but either a shorted Starter Generator or a short in the wiring lead out of the ignition switch.

 

To test the SG, first disconnect the large cable to the SG "A" terminal. Use car jumper cables to connect the battery to the SG. Positive battery cable to SG "A" terminal and the negative battery to the engine ground. The SG should turn over nicely without any excessive current draw or smoking the battery cables. Regardless of if the engine and SG turn over by hand, the SG could still be shorted internally. If the SG does not turn over nicely when connected thru jumper cables (or if the jumper cables start to get warm), stop the test and investigate the SG. 

wiring looks right too me I agree with SOL you have a short

Edited August 21, 2013 by buckrancher

[Jeff-C175 7,195]

It is probably a good idea to add a warning or three at this point...

 

IF the S/G actually IS shorted, when you hit that lug with the jumper cable, sparks will fly!  Be prepared for that and don't burn yourself with flying molten metal!

 

It is possible to 'weld' the jumper cable to the S/G post if this is the case, again, be prepared.

 

Lead acid batteries do NOT like to be shorted out!  Do not perform any test any longer than necessary to determine good or bad.  Shorted batteries have been known to BLOW!

[WheelHorse79 271]

I finally had some time to jump the S/G.  I tried it with 2 different batteries and both times I got sparks at the engine ground and the S/G post, but no cranking.  Not even a click, hum or an attempt to turn.  So, it looks like the S/G is dead.  This is surprising to me because the S/G was working fine before I took the engine off the tractor.  The only thing I did was paint it, and I masked off the terminals to ensure they weren't painted.  I guess I will have to either repair or replace the S/G.  Any suggestions on where to get it repaired?  I could also try to find another one on ebay.

 

Thanks again everyone for your help.  I really appreciate this community and everyone's willingness to help!