Hi, Aron before testing any electrical component in the Starting System it is "IMPERATIVE" that you have a fully charged battery of 12.5 volts or more and be able to pass a proper "LOAD" test if necessary, you may have a preliminary reading of 12.5 volts or more but little or zero amperage, the battery is faulty and must be replaced. AGM type batteries fall into this scenario more so than lead acid batteries.
1. Ignition Switch not in the "ON" position.
2. Engine Run Switch in the "OFF" position.
3. Check the battery terminals for damage or corrosion check the battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter.
4. Bank angle sensor needs a reset or is faulty.
5. FOB battery low or dead.
6. Faulty ignition switch.
7. Faulty starter button.
8. Faulty kickstand, clutch, neutral safety switch.
9. Security alarm needs a reset.
10. Starter relay, solenoid, starter motor or circuit wiring faulty.
11. Starter armature or field coils have failed.
12. Main fuse or circuit breaker may be blown or faulty.
13. Faulty ignition relay.
14. The electric starter is working but starter clutch has failed.
15. Check for engine trouble codes.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
Troubleshooting bike that wont crank
Starter clicking repeatedly but won turn over Not the battery Any help
Yamaha XS1100SH Service Manual
OEM parts for Yamaha
Yamaha 1979 XS1100E Owner Manual
Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e