My B2100 had the same starting problems that many users have described , without an electrical diagram it is difficult to properly diagnose the faulty parts. By profession I work with electricity of all types as an instrumentation engineer.
The culprit above all else is THE IGNITION SWITCH ..the diagram clearly points it out .Because there is no intermediate relay between the ignition switch contacts that lead to the starter solenoid positive lug , the ignition switch contacts will arc for years before enough resistance builds that will prevent the full 12.8 volts needed for the solenoid to completely engage the starter brushes .That is what most people are hearing when they hear the click,it is the partial engagement of the solenoid not the entire engagement...at 7 to 8 volt it to the positive lug the solenoid will make noise but it is not fully engaged. Replace the ignition switch and the problem is solved . the starter in my tractor is the original 1996 mitsu... it will flip the tractor over it is that strong ..of course having a strong battery cannot be ignored and a charging dynamo that puts out 14 plus volts is also a must for battery health . I also recommend to anyone who is experiencing this problem
to buy a can of DETOX electrical contact cleaner , you can do this before or after changing the ignition switch. Disconnect each Molex plug of the safety switches spray the lugs and reassemble, clean all three major chassis grounds ,the battery negative, the one group under the seat and the group on the injection pump side of the engine and all engine sending units. Remove the dash do the same with the rectifier plug and replace the "offending ignition switch". As soon as it is convenient throw the old switch in the camp fire while having a beer of choice ..it may make up for all the aggravation it caused many of you .I use my tractor around the house, it has a backhoe and I have lots of fun with it , sometimes we all just use these things but forget that electrical contacts can oxidize , some climates are worse than others ..but electrical arcing is the worst thing that can happen to any set of contacts and one of the toughest to diagnose.
start enjoying yours again .
YKW54
The culprit above all else is THE IGNITION SWITCH ..the diagram clearly points it out .Because there is no intermediate relay between the ignition switch contacts that lead to the starter solenoid positive lug , the ignition switch contacts will arc for years before enough resistance builds that will prevent the full 12.8 volts needed for the solenoid to completely engage the starter brushes .That is what most people are hearing when they hear the click,it is the partial engagement of the solenoid not the entire engagement...at 7 to 8 volt it to the positive lug the solenoid will make noise but it is not fully engaged. Replace the ignition switch and the problem is solved . the starter in my tractor is the original 1996 mitsu... it will flip the tractor over it is that strong ..of course having a strong battery cannot be ignored and a charging dynamo that puts out 14 plus volts is also a must for battery health . I also recommend to anyone who is experiencing this problem
to buy a can of DETOX electrical contact cleaner , you can do this before or after changing the ignition switch. Disconnect each Molex plug of the safety switches spray the lugs and reassemble, clean all three major chassis grounds ,the battery negative, the one group under the seat and the group on the injection pump side of the engine and all engine sending units. Remove the dash do the same with the rectifier plug and replace the "offending ignition switch". As soon as it is convenient throw the old switch in the camp fire while having a beer of choice ..it may make up for all the aggravation it caused many of you .I use my tractor around the house, it has a backhoe and I have lots of fun with it , sometimes we all just use these things but forget that electrical contacts can oxidize , some climates are worse than others ..but electrical arcing is the worst thing that can happen to any set of contacts and one of the toughest to diagnose.
start enjoying yours again .
YKW54