My truck won't crank it tries but it seems like the batteries are low voltage was good on them but dropped when trying to crank all guages shoot to left when key is turned then fall back in place also sounds like rattling noise coming from pump mounted on wall of passenger side under hood starter kicks in but seems like not enough ump to start it up I need help on this one big time thanks

Remove both batteries and place them on a charger. If the charger's ammeter does not cut back substantially, replace batteries. Be sure to clean the battery terminals and connectors with a battery terminal brush.