Well i have some new diagnosis info to say about my F-90BT. Today I was pissing around with my deck and did some stuff like one guy earlier mentioned about ther beying some sort of voltage fluctuations. I went to the shop and got my batteries tested, and altorrnator looked at. everything was in good working order(so I was told). As for it maby beying a ground issue, I ran a new wire from the dash threw the firewall and down under my truck cab to the flat steel cable that grounds my cab to the frame. I removed the bolt, cleaned boath surfases of the frame and cable with a steel brush and tighte