Battery not charging

2003 MAZDA TRIBUTE

120,000 MILES • 6 CYL • FWD • AUTOMATIC

K5CQB

MEMBER
2 POSTS

The alternator appears to not be working. The battery voltage with the engine off is 12.7 volts. When started the voltage jumps to 12.9 volts then quickly returns to 12.7v.

The battery warning light is not on when the vehicle is running. When I turn the ignition to the on position without starting the battery lights comes on for a fraction of a second then disappears. The other lights stay on but not this one.

I have checked the alternator fuse in the engine compartment fuse box and it's OK. The battery cables are all clean and the connections are tight.

Aug 6, 2010 at 11:41 PM

MHPAUTOS

✓ASE Certified Mechanic
31,937 POSTS

Hi there,

The alternator has an internal failure, possibly a faulty regulator, get a rebuilt alternator this should fix your problem.

Here is a guide to help you step be step to change it out.

https://www.2carpros.com/articles/how-to-replace-an-alternator

Mark (mhpautos)

Aug 7, 2010 at 12:10 AM

K5CQB

MEMBER
2 POSTS

Thanks, it was the alternator.

Just a tip here. If you buy an alternator have the seller test it before you leave the store. The brand new alternator I bought tested bad. Since I had to remove the wheel spindle and axle to get to the alternator I would have lost my composure if I put the bad one in only to find it didn't work.

Aug 8, 2010 at 2:19 PM

MHPAUTOS

✓ASE Certified Mechanic
31,937 POSTS

Hi there, not the first time ihave hard this happening, good luck with it.

Mark (mhpautos)

Aug 8, 2010 at 4:31 PM

ROBINWALDREP

MEMBER
1 POST

I put two new alternators & a new battery, the first alternator was bad and the second alternator I had tested before I left the store it tested good but its still not charging. What could be the problem?

Dec 31, 2018 at 10:54 AM (Merged)

JOHNNYT73

✓ASE Certified Mechanic
924 POSTS

Check the fuse panel under the hood and check the larger fuses. It may be 100 amp - 120amp fuse that completes your charging circuit.

Dec 31, 2018 at 10:54 AM (Merged)

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