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Hey guys and gals.
In desperate need of some help.
Sent my Bobcat 36 classic walk behind out for some what I thought was going to be some simple work. Simply had wanted to hook the battery and new key switch I had purchased to the stator so it would charge.. The guy said over the weekend he would have it taken care of.. NOOO problem he said... Well 6 weeks later (late last fall) he finally came back and dropped it off. got paid. machine seemed to start right up. (had new battery) used it. Went back out following couple days later and dead. charged it.. used it. dead next day. Bought new battery, happened again. So now i'm in a jam. He cut my entire harness out of the machine and had a jumble of wires and butt connectors everywhere. And my inline fuse holder was gone. So here is a picture of all the items I'm trying to connect up to make it work. And somewhere in there I would think I'll have to put the fuse back in. There's also the issue of a kill switch that is activated when you release the levers on the handle. (he took the levers completely off and gave them to me in a box.. ) Any electrical guys out there? I'm not good with the wiring part. I could rebuild the motor though...Sorry such a long post but am hoping to give you as much info as possible.

Download this guide from Briggs & Stratton Alternator replacement guide
It contains everything you need to know and towards the back has generic wiring diagrams for most set ups
If you get stuck came back & ask questions.
The more question the better.
If you work from that book then we all will have the same information which makes things easier for every one.
Now for safety sake do not connect the magneto wire till everything is connected and then check that no matter what you do, the kill wire never ever has any voltage on it .
If this happens in use the magneto modules ( coils ) will be fried and they are not a repairable part .

Key switch codes
M = magneto kill wire
B = battery ( power in ) which should be fused
X = A ? should have the regulated rectified feed from the alternator
G= Ground
S= Start
L = lights

bertsmobile1 said:

Download this guide from Briggs & Stratton Alternator replacement guide
It contains everything you need to know and towards the back has generic wiring diagrams for most set ups
If you get stuck came back & ask questions.
The more question the better.
If you work from that book then we all will have the same information which makes things easier for every one.
Now for safety sake do not connect the magneto wire till everything is connected and then check that no matter what you do, the kill wire never ever has any voltage on it .
If this happens in use the magneto modules ( coils ) will be fried and they are not a repairable part .

Click to expand...

Thanks, downloading it this morning and going to just print it out. I looked and it does have a diagram like mine in there. Going to check to see if i've already "fried" anything.... one question though, in your next reply you listing the "L" on the switch as lights. The diagram i'm seeing has the "L" for the carb solenoid. I realize if I had lights I could use it for that purpose. So I suppose the next step is to bench check the coil, Rectifier, and magneto. I also found a old harness off a lesco I had. Going to check it out and see what can and cannot be used off of it. Thanks.

Take a few pics of what you have too, it will help us in helping you.

Depends upon the actual mower.
If it has an AC lighting circuit the L connected the lights to the ground .
As you have a walk behind I assume there are no lights on it.
The booklet has the interconnections for different switches .
Some switches have A1 , A2 , L 1 & L2 terminals
There are quite a few variations
However G,M,S,B & A are always wired the same G + M for stop & B+S for start .
If you have a solenoid then it has to be energised from one of the pins that is connected to the B terminal when the engine is going & open circuit when stopped.
The only complicated bit is the wiring of the PTO switch as it has both 12V for the PTO passing through it and various grounds for the safety circuits.
Usually the pins closest to the knob ae the start circuit and all the rest are the PTO & Safeties.
A lot of PTO's are wired directly to the battery with the switch making the ground to complete the circuit
But the schematics should show that.
If you are using an old harness you can usually pull the terminals out of the plugs using a thin screwdriver to depress the barbs then giving thee wire a sharp pull .
I use a "special tool" which is a 0.045" feeler ground down to be a close ift in the slot and ground to a single sides knife edge.
Push the terminals forward to get some clearance between the barb & the retaining tap then push the tool in and jag the wire back .

To test the coil, pull the plug and flick the flywheel magnet past the coil.
It should throw a spark.
You can even use an electric screwdriver / drill with a socket driving the flywheel retainer.
In air it should throw a spark of around 1/2 between the wire &the block ( no plug )
If it throws no spark at all then the coil is toast .
Very few can be tested with an Ohm meter because of the trigger chip .

So hopefully these pics will help

Will not have an AC circuit due to having a Tri-circuit stator and regulator.

Need the model number to look-up the mower parts. Need know to what switch it is using.

Briggs # 28bh11760114e code 030827za 15.5 ohv

So you have a keyswitch and on/off switch?

When you turn your keyswitch to the off position. the solenoid on the bottom of the carb should make a clicking noise. If not, unplug it and see if it clicks. It might be what is running the battery down.

Yes. I probably do not need both. Originally this mower did not have a starter or a battery. Had a mounting spot for a starter. I built a tray for a battery. To much to pull when trying to get it started. Four shoulder surgery's to date...

madman said:

Yes. I probably do not need both. Originally this mower did not have a starter or a battery. Had a mounting spot for a starter. I built a tray for a battery. To much to pull when trying to get it started. Four shoulder surgery's to date...

Click to expand...

or a key switch. Just the on off (black ) switch

A 28BH76-0114-E1? THat get the engine. What about the mower itself? Needing to switch ignition you have part number for interconnects.

madman said:

Yes. I probably do not need both. Originally this mower did not have a starter or a battery. Had a mounting spot for a starter. I built a tray for a battery. To much to pull when trying to get it started. Four shoulder surgery's to date...

Click to expand...

What about the solenoid on the carb?

Put an inline disconnect on both of these wires, so you can unplug them when not in use. I circled them in blue.

Fish said:

What about the solenoid on the carb?

Click to expand...

This machine always had the solenoid on the carb. And I was under the impression that on a single lead wire stator if I had a rectifier and was working correctly that it not only would restrict the back flow from the battery but also convert ac to dc. Is this not correct? But From what I also gather there is no bench test for a rectifier. Only if the machine is already running.
Also there was a reply with two circles around two red leads coming off of the coil. One lead is not being used. That the only wire this guy didn't cut and left the connector on. The other wire i'm assuming is now my hot lead for everything with the exception of the starter. I believe I found a diagram on the briggs site as suggested. I'm going to post it to find out what everyones thoughts are. I'm still in the dark a bit on my pto switch. I understand the concept of normally open and normally closed. Just confused as to which wires go where on the pto switch and at what sequence the power/grounds ect. go through it.
I do not have lights. so I'm assuming a pigtail from the out going wire off of the rectifier to the carb solenoid.

Pin of the PTO switch you have is as (with right side being commons)

If the rectifier is a simple diode it is bench testable. Low resistance forward biased and high resistance reversed biased. If regulator/ rectifier setup then it is only testable in operation, either works or not.

The reason asked which switch your have. Different switches have different modes of contacts in off, run, and start positions. Just looking at physically doesn't show how it works internally.

StarTech said:

Pin of the PTO switch you have is as (with right side being commons)
View attachment 51865
If the rectifier is a simple diode it is bench testable. Low resistance forward biased and high resistance reversed biased. If regulator/ rectifier setup then it is only testable in operation, either works or not.

The reason asked which switch your have. Different switches have different modes of contacts in off, run, and start positions. Just looking at physically doesn't show how it works internally.

Click to expand...

Supposedly this is the order on the switch. He replaced that as well and just marked on the sides of it the alph pattern. There are no stamped letters on the blades or the housing.

madman said:

Supposedly this is the order on the switch. He replaced that as well and just marked on the sides of it the alph pattern. There are no stamped letters on the blades or the housing.

Click to expand...

And I finally found a schematic which I believe is correct to at least the original wiring of the machine. Think I'm going to go to this guys house and take a pair of linesman plyers to every wire coming out of his power panel.... kidding.

Does the carb solenoid make a click when you turn the key on and off?

Carefully check the connection on that switch he fitted.
I have never seen a mower switch that is not labled.
But very few car switches are labled
Only mower & boat switches have a ground wire fitting to turn off the magneto
If he has fitted a car switch then it only connects various pins to power and you don't want power going to the magneto kill wire.