Combines 9500 cb shutting off head

Sounds like RF flowing back on the Co-ax braid that goes to the CB. Check the cable and make sure it is connected properly to the co-ax connector, If you know someone who is a HAM operator he may have an SWR meter you can borrow, this will check both the condition of the cable and the antenna tuning. Both will cause stray RF.

The problem lies in your armrest circuit board. If your dealer had any product knowledge, he_she would have told you about this.

On some machines, The single point ground has a nut that is loose. This ground is located behind the pannel on the rh side of the combine-where all the cab connectors are. You might have to dig under a a_c duct on older machines to find the wires and stud. Have had some combines go to low or mid idle when using the 2 way with this ground problem, one guy had used the small wires behind the seat for radio power and had your results, but you did say you re-wired it.