Alternator Battery***HELP***

[mike79]

Two days ago while driving my radio went out and the ABS light came on. Five minutes later I pulled over, turned the car off and it wouldnt start.

All the diodes in the alternator went, and my battery was shot. So I had the stocker rebuilt, and bought a new battery. After 20 miles of driving, the battery light comes on, and its now barely turning over.

What could this be? A short?

 

[Top_Fuel]

You replaced everything with new parts, but are you sure everything is working? There's a chance your newly-rebuilt alternator isn't charging...or your new battery may not be any good. It's happened before.

Do you have access to a digital multi-meter? HERE is one at Harbor Freight for $4.99! :-D It doesn't have to be anything fancy. You can do a few quick "shadetree mechanic" checks with a multi-meter to find out what's going on.



Battery Voltage Test

Turn your headlights on for 60 seconds, then turn them off. This will remove the "surface charge" from the battery. Now take the meter and measure DC voltage at the battery terminals with the engine off. You should see 12.6 volts to indicate a 100% charge. If it's 12.4 volts or lower, then the battery is weak. For example, a battery showing only 12.2 volts is only 50% charged! (see THIS link for details). If the battery shows less than 12.6 volts, charge the battery before going on to the next test.


Alternator Charging Test

Using your meter, measure DC voltage at the battery terminals while the engine is running about 2000 rpms. You should see 13.5-15 volts. If you see less than this, the alternator is not charging properly.

 

[mike79]

Batts good. Alt isnt reading when we checked.

 

[mike79]

Bushing wasnt making contact inside the alternator...go figure! Thanks Top Fuel for the help though!