a little dx9 help

[bigford]

so I want to switch between my trucks all 3 are on
1) I scroll to system set up
2) click yes
3) model select
4) now here is where the problem is....
my dump truck and quad king both shoot into reverse once the rf signal
is lost. the peterbilt don't move at all. I have the throttle cut set to 0%
on the C switch 0ff 0n 0ff. all the trucks are set up the same viper 15 esc
rc4wd 65 turn motors

the two trucks will do this with the throttle cut off set to on or off
I cant have fly away trucks at cabin fever

HELP!!!!!!!