Alternator charging too high

[Mattgyver]

Ok so I changed my alternators out a few months ago when they went out. I have been watching how high they have been charging because I feared maybe there was any electrical problem and thats why they went out last time... I noticed today that one of my alternators is charging my battery at around 19.6 but the other one is charging at around 14. Anyone know what might be wrong so that I dont burn out both alternators again? Thanks

 

[doghead]

When you say you "changed out" your alternators, did you replace them with new or rebuilt alts?

 

[Mattgyver]

New alternators... ive had a similar problem on a toyota truck i had also.. i went through 3 alternators before giving up

 

[doghead]

Where did you buy new isolated ground, alternators from?

 

[Mattgyver]

OD Iron LLC Military Vehicle Parts and Accessories

 

[doghead]

Pretty sure he offers a warranty, have you asked about getting a replacement?

 

[Mattgyver]

No, not yet because Im not sure if there is a different problem.. The other alternators went out after a pretty long trip. I took another semi long trip on friday and now its acting up.

 

[hobie237]

Overcharging is a result of a bad voltage regulator. Since this is internal to the alternator, the choices are to A) rebuild or B) replace the affected unit. The one around 14 is fine, the one around 19.6 is bad.

Note: This assumes that you are measuring from the output to the isolated ground of each alternator. If measuring from the output to chassis ground, #1 should show around 14 and #2 around 28. If that's how you're measuring, then the alternator showing 19.6 is still bad, but in a different way. Same choices of action, though.