Battery keeps going down alternator and battery

Well, something is draining the battery. Recharge the battery, and have it load tested. If that tests okay, check for voltage draws while the car is off. Pull all fuses, test again. Alternator diodes are a common culprit and would not stop the draw with all fuses pulled. Keep going until you identify the offending system.

Charge the battery start the engine and confirm that the voltage at the battery is about 14 volts with engine running . If not it is likely the alternator is bad or the electrical connections from the alternator to the battery are defective.

A significant drain from the battery can be determined by observing the battery voltage after stopping the engine.

If it is under 12 and continues to drop trouble shoot for battery drain. If you suspect the radio pull the fuse and observe.

CHECK ALTERNATOR DRIVE BELT TENSION IF BELT LOOK LOOSE ADJUST DRIVE BELT TENSION.IF YOU HAVE AUTOMATIC BELT TENSIONER CHECK FOR FOR BROKEN BELT TENSIONER. IF DRIVE BELT LOOK OKAY.CHECK ALTERNATOR VOLTAGE OUT PUT AT BATTERY WHILE ENGINE IDLING.BATTERY VOLTAGE SHOULD BE 13.5 - 14.5 VOLTS. IF NOT ALTERNATOR FAULTY.FIRST CHECK ALTERNATOR FUSE AND CHECK ALTERNATOR POWER FEED WIRE AND VOLTAGE REGULATOR WIRES FOR DAMAGE OR LOOSE CONNECTIONS. FIRST TURN OFF RADIO BEFORE REMOVING NEGATIVE BATTERY CABLE TO KEEP FROM LOCKING OUT RADIO.

Check the cable connections to the battery. If they are loose or dirty, clean them and tighten them. Check the battery for water while you are at it.

If that is okay, have an auto parts store check your charging system - they do it for free. You could be in the early stages of alternator failure or diode failure.

I had a van that did this for years but was always leery of it.

CHECK ALTERNATOR 175 AMP MEGA FUSE. AND CHECK ALTERNATOR 20 AMP INLINE FUSE.IF FUSES OKAY.REPLACE BATTERY CABLES AND CHECK ALTERNATOR BATTERY FEED WIRE AND VOLTAGE REGULATOR WIRES FOR DAMAGE.AND CHECK DRIVE TENSION.MAKE SURE DRIVE BELT NOT DAMAGE OR SLIPPING.

check to see alternator charging battery.with engine running alternator out put at the battery should be 13.5 to 14.5 volts.check alternator drive belt, should be checked or changed at 60000 miles intervals.all drive belts should be checked at 60000 miles.if drive belt okay has correct tension have battery load tested it could be going bad.turn off radio first if you disconnect negative battery cable.reason i warn every body to do that so you wont lose radio playing code.

you need to have a mechanic, install ampmeter and check the parasidic draw with engine off!! something must be staying on, and drawing battery down. have a good holiday !!

Well, you start with the battery. It needs to be FULLY charged, that means about 4 to 6 hours on a real charger. Then you load test the battery.
If battery checks out okay, pull the alternator and have it bench tested, specifically test the diodes for open.

To narrow down the offending system/item: pull interior light fuse, and clock fuse, disconnect negative battery terminal, and put a light between the cable and the battery terminal (or a volt meter). if the light lights or you show voltage, disconnect circuits, one at a time, and retest....Eventually you will find the offending item.

Make sure wire conections to alternator are clean and secure. If it's still not charging properly at idle then alternator might need repair. Also make sure engine oil level is okay.

Computer is out. The voltage regulator is in the computer.