QuestionQUESTION: I have a craftsman 24 hp 50 in. deck lawn tractor that wont start. checked for voltage after the ignition switch was turned on at the starter and had voltage. went from the starter to the 2 diodes connected and had voltage. had no voltage on the other side of the diodes which I suspect are blown. No voltage prevents the fuel cutoff solenoid from opening preventing gas flow. Also there is a operator presence switch , will that cause the mover from not starting if no one is sitting on the mower. Need some help. Either the diodes or the seat switch is preventing it from starting. So far I removed the fuel shut off solenoid and noticed it was rusted preventing the solenoid from working. Cleaned out the solenoid and made sure it was mechanically operational. Tested it with a 9V battery to see if it open and closed with voltage and it did. tested the diodes and they were both reading "open". I suspect the solenoid had a over current issue which blew the diodes. Now i am trying to track down the diodes to replace them in the wiring harness. Model or Part number 981N5. Any clue how i can find a replacement for these diodes?
So far I removed the fuel shut off solniod and noticed it was rusted preventing the solid from working. Cleaned out the solenoid and made sure it was mechanically operational. Tested it with a 9V battery to see if it open and closed with voltage and it did. tested the diodes and they were both reading "open". I suspect the solenoid had a over current issue which blew the diodes. Now i am trying to track down the diodes to replace them in the wiring harness. Model or Part number 981N5. Any clue how i can find a replacement for these diodes
ANSWER: Do you have a Kohler CV26S-69526 engine?
Where are these diodes? On the mower chasis wiring harness or the engine wiring harness?
Eric
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QUESTION: Thank You Eric..
Yes, the motor is a Kohler CV26S-69526 engine.The diodes are on the motor wiring harness. 1 wire comes from the starter to the anode side of one of the diodes and another comes from ignition switch. Both diodes are tied together at the cathode and has 2 wires coming from the cathode side of the diodes to the fuel shut solenoid and the other to the regulator rectifier..
ANSWER: This service manual may help:
http://www.kohlerengines.com/onlinecatalog/pdf/sm_24_690_07.pdf
Kohler diode kit?
http://www.ebay.com/itm/KOHLER-Diode-Kit-25-755-31-S-/170889051749?pt=LH_Default
If it were me I would go down to Radio Shack and buy a couple of diodes that look the same size. I've had trouble sourcing OEM diodes in the past and just ended up using Radio Shack diodes.
Eric
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QUESTION: Thanks Eric.. This information was very helpful. I guess i need to know if there should be voltage going across the diodes to the fuel shut off solenoid?
I get 12v dc up to the diode and on the cathode side which would connect to the solenoid nothing. On the schematics both diodes are tied together so I disconnected each diode and measured the voltage. Still getting voltage on one side and nothing on the solenoid side???? Am I missing something!
AnswerDid you test each diode, with one side of the diode dis-connected, with and ohm meter?
You should have some DC voltage on the cathode side of the diode.
http://www.allaboutcircuits.com/vol_3/chpt_3/2.html
I'm still wondering why the diodes are there. Briggs has a couple of Vanguard Twins with dual coils and they have 2 diodes between the coils to eliminate AC cross feed between the coils.
But the solenoid is a DC device. If the solenoid is connected to the AC side of the alternator then as least one diode would be needed to covert the AC to DC.
I'd still go to Radio Shack and get a couple of diodes. Since you have one side of the diode dis-connected I'd connect a new diode to the circuit and see if you get DC voltage on the cathode side.
Eric
