Replaced battery and alternator. car runs and either dies or I turn it off and the battery is dead. I have started it and pull the positive battery cable and engine will die

Sounds like the battery is dead and the alternator is not putting out power. The truck runs off the alternator after it starts. The battery is just there to start the truck. Try to jump start the truck again and once it is running take the positive cable off the battery and if it stops running you have a problem with the alternator.

Sounds like your alternators dead with the car running take the positive lead off the battery ifbit dies alternator is bad

Charging voltage should be around 14 volts or more for battery to be properly charged. If significantly below that the alternator is not working properly.

• If it starts with the aid of a jump start and dies as soon as the jumper cables are removed then your battery clearly needs replaced.

• When you put the new battery in you can have someone start the car for you and then you can remove the positive cable off of your battery (while the car is running). If the car stays running turn the defrost on and the headlights and this is called testing the alternator under a load.

• The alternator should support the functions of the car and the car running with no support from the battery. The battery is only for starting the vehicle.

• If during this entire test the car stays running then the alternator is good. If the car dies at all the the alternator is bad and needs replaced.

• If you have any comments please free to leave them here.
• Hope this helps and thank you for using FixYa.

Regards, Tony

I would change the alternator if the battery keeps dying.

you alternator is no good to ceck alternator start car while running take off positive cable if it dies your alternator is no good but thats what it sounds like

It sounds like the Alternator is actually bad.
One great way to determine this:
Recharge the new battery with a trickle charge overnight. Make sure use remove the wires going to the Battery before recharging.
Replace the Battery Wires.
Get the Vehicle Started.
When it has Started: Leave it Running and Disconnect and Remove the Negative side of the Battery. If the Vehicle dies, it is the Alternator that is bad, and needs to be replaced..
The Battery starts that vehicle, and provides nominal power to certain accessories. The Alternator actual Runs the Engine and Recharges the Battery with a low trickled charge.

Your alternator is faulty.

bad silonoid on starter
the actual cable on starter is bad even though you replaced the positive battery connector the whole cable could be bad
also your new battery might not be a heat battery example= a battery that cannot handle heat and will die on you this indicates a dead cell in battery
bad alternator not charging battery
bad ignition coil
scorched spark plug wiring
dead cell in battery even though the battery can show good it can still be bad
battery's these days are usually refurbished battery's practically every one recycles batterys so its a chance that you got a bad battery try a jump then while vehicle running disconnect the positive post of battery if vehicle dies its the alternator

i myself had to do a battery swap 4 times before i got a refurbished battery without a dead cell this something that is a pain but once you get a good battery then everything should work