The most common cause of a battery not holding its charge is corroded battery cables. That is the end of the cable which connects to the battery. The battery has a post that sticks up and the cable ends in a hole. The hole in the connector is pushed down over the post and is tightened with a bolt on the cable end connector.
When this connection gets corroded, the higher resistance prevents the battery from receiving the normal amount of current from the alternator and so gradually it dies.
You can buy a gizmo at any auto store that is designed to clean both the post and the connector with the hole. One end does the post and the other does the hole.
BTW, I learned about this from my mechanic who always looked for the simplest explanation for a problem first, and thereby saved his customers a lot of money.
run it and then disconnect the negative wire from the battery if alternator dies its bad.
To test the alternator if funds are low, let the motor idle and remove the negative battery cable, if the motor dies its probably the alternator.
Why do you want to unhook your battery??? If the alternator is good the car will continue to run, if it dies then you have a bad alternator this is why you would want to unhook the battery cable to check and see if you have a bad alternator
If the alternator is good then the battery is bad.
This could also be alternator problems as in a bad diode in the alternator.
If the car won't start, jump it off. While it is running, remove the positive cable from the battery. If the car dies, then your alternator is bad. If it keeps running then you may have a bad battery.
probably have a bad alternator or voltage regulator or bad battery cables
Battery light usually means alternator not charging. Most common solutions would be be a bad alternator, bad connection, or loose alternator belt. A replacement alternator can be bad. If it is ok than most likely a poor connection to the alternator.
Possibly a bad alternator or battery.
Start the truck then disconnect the battery if it's still running the alternator is good
Generally, yes.
You probably have a bad battery. You probably have a bad battery.