2002 Tiger Cub won't crank

[estebank]

I have a 2002 Tiger Cub with a Kawasaki engine. The FH640V has been replaced with an FH680V.
Model_STC48A-21KA
SN_7650820
The unit has had an intermittent issue that seemed as though it was a switch issue. Turning the key would only result in starter clicking. Repeated attempts would eventually result in an immediate good start. Yesterday the machine was working fine with many repeated starts(some with apparent key issue). Next morning the machine would not crank. With the flywheel cover off I can observe the starter gear. The starter extends but does not turn. I have a spare starter that I installed. Both starters and the battery tested good at O'Reillys. Both starters respond the same even when using an automobile to jump start. I tried replacing the relay with the same result. All wiring seems to test good. Key switch was replaced and no change. I tried using a starter button to bypass all controls and had no good luck. The battery is old but was starting the machine just fine just yesterday, it seems that if it will not jump start that eliminates the battery as an issue. I do not know what else to try. The only thing I have not tried is replacing the interlock module as it is expensive. I will add that this issue has been going on, intermittently, for quite a while. I sure could use some fresh ideas on this issue as it has me tearing out what little hair I have left out.

 

[StarTech]

You got a voltage drop issue in the wiring. IE bad ground or other bad terminal connection. Perform voltage drop tests to where the problem lays. If the starter solenoid on a solenoid doesn't fully engages it will not power the starter motor via the internal contacts..

 

[estebank]

I have been using only a test light to prove circuits so far. I cleaned the engine ground connections previously because I had suspected grounding issue earlier because when testing at auto parts store the starter would not work until it had a good ground. I am not sure where to start testing. How about a jumper from battery (-) to Grn/Blck at interlock module with module unplugged. Or, suspect Rd/Yl wire to solenoid. Any thoughts on where to start testing voltage drop.

 

[estebank]

Do I need to check voltage drop when trying to crank. How do I remove wires from plugs? Is there a special tool required? Thanks

 

[StarTech]

Do I need to check voltage drop when trying to crank. How do I remove wires from plugs? Is there a special tool required? Thanks

Yes as that when you having the problem.

To remove it is simply twisting and pulling at the same time normally as the boots and terminals can stick.

 

[estebank]

Eureka!! With your steering me in the right direction I found the problem in about 5 minutes. It was a loose connection leaving the fuse supplying the power to the relay. When the circuit was energized, the voltage dropped to 9Vdc. I redid the connections and it is back to running like a champ. Thank you so much for your assistance. This problem has been vexing me for some time now as it would come and go. Apparently when operating the keyswitch, sometimes I would put pressure on the wiring at just the right place. On these old machines the fuses are dangling right by the switch. They have been replaced before and I guess the connections loosened over time. Again, thanks a lot for your advice.