A failsafe is some sort of electronic gadget any nitrohead should have on their car. If you lose signal or your reciever batteries get too low it clamps the brakes on. Mine has kept my nitros from running off many a time.



But since you don't have one, I'd try reversing the connections at the reciever. If the problem goes to the steering servo, your radio gear is at fault. If it stays at the throttle servo, then the throttle servo is kaput.