New battery, new alternator still won`t hold a charge

get a new battery or if not that a new alternator or high resistance in the wires that charge your battery

CHECK WIRING THIS UNIT WILL CONTORT THE FIELD IN THE COMPUTER. THE FIELD CONTROL IS WHAT MAKES IT CHARGE.

voltage regulator. it may be in the alternator, or remote mounted. ((the alternator can be charging, but if voltage regulator is'nt working then it won't allow voltage to get back to the battery to keep it charged

Depends.
If the alternator is charging, and the battery will not hold a charge, I would suspect the battery.
If the alternator is not charging the battery, I would look at the fuseable links and connections.

Sounds like you have a toasted battery or alternator. Have you performed a load test on the battery? Have you tried to charge the battery? First remove the battery and charge it externally from the vehicle. If the battery won't hold a charge, or won't hold a charge of 12 volts, replace it. Once you have the vehicle started, test the operation of the alternator. It should be putting out at least 13 volts back to the battery to keep it charged - if it is putting less than 13 volts or more than 16 volts, replace the alternator.

Ya, when the car is running, you're using power from the alternator. So it will show 14 volts as long as its running. The fact that it won't hold the charge means the battery is shot and you probably need a new one

YOUR ALTERNATOR NOT WORKING.HAVE BATTERY CHARGED UP.YOU SHOULD HAVE 12.6 VOLTS IF BATTERY FULLY CHARGED OR NEW.START THE ENGINE.WITH ENGINE IDLING YOU SHOULD HAVE 13.5 - 14.5 VOLTS AT THE BATTERY.IF NOT.ALTERNATOR NOT CHARGING BATTERY.BEFORE REPLACING ALTERNATOR, MAKE SURE DRIVE BELT NOT SLIPPING,CHECK ALTERNATOR FUSE,CHECK ALTERNATOR POWER FEED WIRE AND VOLTAGE REGULATOR WIRES FOR DAMAGE AND LOOSE CONNECTIONS. BEFORE DISCONNECTING NEGATIVE BATTERY CABLE TO MAKE REPAIR, TURN OFF RADIO FIRST TO KEEP FROM LOCKING IT OUT.

Hello and welcome to FixYa!

If the battery light is on, I strongly suggest that you have the battery charged. It can be an indication of a weak battery or a faulty alternator. If the battery light still on after charging then the problem will surely be on the alternator itself. If that's the case the alternator should be replaced to resolve the problem.

If the battery won't hold charge even on a new alternator then the problem will be on the battery itself. It surely is in the end of it's service life and replacement will be necessary.

You may try to reset it to by removing the positive battery connector, letting it sit for at least 5mins. then reconnect it again. This will reset the system and can get the battery light off.

Hope this helps and thank you for using FixYa! Have a good one!

Check battery for voltage when is not runing and when is runing.Possible battery lead's shorted and wont hold charge.

its the battery. the battery holds the charge and the alternator charges it so when you jump the car it stays running because you alternator is providing power when you shut the car off you have a bad battery that isnt holding the charge needed to start it again.