I Developed a stumble or surge with the TST at high speed set on the higher levels so I called the company and spoke with Mark. I was given information that the Alt might be going bad and sending a spike in the line. I disconnected the Alt and Bam no more stumble. So the Alt charges fine I thought about the problem and installed a 1000 uf electrolytic capacitor with a 50 ohm resistor to the fused wire with the + side of the cap to the line and the other lead to the resistor and the other lead from the resistor to ground and Bam no more stumble. Just a thought Damon