Electrical Problem with 425

[BobRip]

Glad you found it. I agree with your diagnosis. J2 jumpers to the lights. Unless your fuel solenoid is wired wrong, then it should not be needed. You should trace the fuel solenoid wire and make sure it goes to L, so it will be on during cranking.

 

[J_J]

BobRip, JJ,
Find the problem..........bad keyswitch. After downloading the Kohler manual and studying it and BobRips electrical diagram, I made some more measurements. The keyswitch does not make contact in the "start" position.

I pulled off the switch and used some jumper wires to short the appropriate points together. See the attached diagram. Once I did this it started right up.

One thing I don't understand (I think the Kohler electrical diagram is not correct for PT425) is if jumper J2 is not connected then the starter & solenoid works but the engine will not start, like not fire to the plugs and the lights do not work. With jumper J2 connected the engine starts right up and the lights work. Once the engine is running I can disconnect J2 and the engine keeps running but the lights do not work. What is J2 doing?

My PTmanual says the keyswitch is a Robin E341x1. Where can I get one (besides PT)?

Thanks for all the inputs from everyone.
-Tim

On the back of the switch, what is the letter designition for the terminal you have a question mark ?

Some common terminal ID is

B----BATTERY
M----MAGNETO
L----LOAD
A----ACCESSORY
G----GROUND
R----RECTIFIER
S----STARTER

The G terminal is not used if mounted on metal that is grounded, because it is internally grounded. The G terminal is used if the switch is mounted on a non grounded plate. I found this out the hard way when I had the ign switch laying loose and I touched the switch, and got a good buzz when I went to turn off the switch. The magneto is killed by grounding out the magneto, and therefore stopping the engine. .

 

[tlb]

JJ,
That's the problem, the terminal with the ? on the drawing I attached in a previous post is not labeled. The other 5 terminals have G, S, M, L, and B.
Tha tis why I do not understand what it does. If I do not connect this terminal to B the starter just spins the engine. Once I connect it to B the engine starts fine. After the engine starts I can disconnect it and the engine continues to run. Go figure?

I'm just happy it starts. I used the jumpers today and got in a couple hours of seat time. Doesn't look pretty but at least it works.

-Tim

 

[BobRip]

I looked on my switch and that terminal is for the lights and hour meter.

 

[J_J]

JJ,
That's the problem, the terminal with the ? on the drawing I attached in a previous post is not labeled. The other 5 terminals have G, S, M, L, and B.
Tha tis why I do not understand what it does. If I do not connect this terminal to B the starter just spins the engine. Once I connect it to B the engine starts fine. After the engine starts I can disconnect it and the engine continues to run. Go figure?

I'm just happy it starts. I used the jumpers today and got in a couple hours of seat time. Doesn't look pretty but at least it works.

-Tim

I think this diagram might answer the question, Why.

It seems like there are two inputs for the fuel solenoid, and there are diodes involved to keep 12v where it shouldn't be. It has to do with burning up the ign modules. I ran into this problem many years ago, . You have to have 12v in the start position, and 12v in the run position. I am thinking that PT is using the jumpers to get around this. So if you pull the jumper, It may try and crank and may run while the switch is in the start position, as soon as you let off the start position, there is no more 12v for the solenoid. So by jumping from the batt 12v to that unmarked terminal, , as soon as you leave the start position, you now have 12v to the fuel solenoid and the engine will keep running. I had to make a new wiring harness for my new 25 hp engine to replace the 22hp Kohler engine on my Dixie Chopper. If I remember right, I had to pry this info from some tight fisted techie who wanted to keep the data a secret. Also one more note of caution, there are a lot of ignition switches out there that look similar. If you get the wrong switch, you may fry some expensive component, and you can not normally return electrical components. So think hard and do your homework before you commit.

http://www.kohlerengines.com/common/resources/tp_2450_b.pdf

Sorry about that large file, but insert 120 as the page number.