Joe,
Like many have commented here, there are things throwing them of here. Not to blame anyone, but it could be your description of what's happening, or others experiences of previous failures by comparison. THE EHC is very tricky to diagnose for the average person that is not educated or trained in the field or micro processor based control systems. The EHC's is a micro-processor based input/output controller unit with the added capability of some monitoring (instantaneous LED "fault" indicators) and the saving of "some" of the previous faults into memory. Some of the EHC circuits are nothing more than "pass through" circuits to enable the physical circuit to get into the wiring harnesses or achieve a power source from.
By the term "Pass Through", I mean that the EHC really doesn't provide any form of control to that circuit other than the means of a "path way" for power supplying or actual circuit continuity. The running lights, marker lights, license plate light, oil pressure switch, neutral switch, tach. signal, speedo sensor, and there may be a few others, that I can't remember without looking it up, just achieve a power supply or source from the EHC. "When the Key is turned on to provide power to the EHC, then the EHC power pathways are energised simotaniously to provide power "only" to other components that are not in controlled by the EHC".
The handlebar control buttons functions "Do" control operations through the EHC; Front Brake, Right & Left Turn signals, Run & Off switch and the Start switch.
The EHC LED lights should illuminate (light up) as follows:
Key "ON" and "Run" depressed: should illuminate one LED on the EHC & one on the Ignition module.
If this is not the case, first you should be looking for:
1) open circuit (check "ALL" connectors between the EHC and the hand controls for proper connection & continuity through the connectors.
2) check to see if the hand control PCBs are providing the proper response output "Low Voltage Ground" when a button or switch is depressed.
or
If no power is being used to test, check for proper "continuity" when a button or switch is depressed.
The "low Voltage Ground" or "continuity" will only be present "ONLY" during the time that the button or switch is physically depressed!
Once the proper response ("Low Voltage Ground" or "Continuity") is achieved at the hand signals. Then trace the same wires to the EHC to verify the the same proper response is being received at the EHC inputs.
If the proper responses "ARE" being received at the EHC, and the is "NO" output response when the "RUN" button or switch is depressed, it's very likely that the EHC has failed, "IF ALL OTHER BATTERY CONNECTIONS ARE GOOD TO THE EHC & BATTERY IS VOLTAGE IS CORRECT"!
Hope this helps.
Just my thoughts here.
