First, need to know what you have. The "XR" series are "performance" 150's not 200's. Unless I have worked on it emoBigsmile emoBigsmile
The tac is driven by the stator. If the stator has failed, it will take out both. You could also have a regulator to have gone bad shorting the diode to ground and causing the same issue. There were a few years where mecruy tried a 40 amp system with 2 wires. If those go bad they are around 1K for parts!!!! emoEek I have converted several of them back to 9 amp systems for way less. If you have a 9 or 16 amp system it will have a square regulator on it and they are easily tested with a multimeter. If it is good then the stator is the culprit.