Originally Posted by Tranz4mr
It sounds like you blew the rectifier disk on the d handle. This is usually because the whistle switch is worn and gets stuck on, overheating the disk. On the A side the contacts in the whistle switch either need adjusting or need to be replaced.
Email Tranz4mr at Tranz4mr dot com
I think this is probable. During the return travel of the D whistle, the lever does not fully return to center (about 1/8"). The A side switch is smooth as glass.
From what I can see on the D side, the contacts touch even though the lever doesn't fully return. But I'm thinking I cannot see the faulty part of the switch inside the handle. I looked at the Tranz4mr site. Is there a tutorial someplace for accessing the switch?