after replacing with new battery it did the exact same thing
Your saying when you replaced the battery, it still cranked over very slowly and would not start
1) When was the last time you started it and it cranked over good?
2) If you have two batteries, a coach and a chassis, are you sure you replaced the correct battery?
If your mechanically/electrically inclined, you might consider installing an "EMER START" button, if you don't already have one. This is a momentary switch that energizes the isolator solenoid. If your coach battery is charged, its kind of like "jump starting" your truck battery by using your coach battery.