I recently had the alternator rebuilt, I noticed the other night the lights brightening upon acceleration but quickly returning to normal after the brief spike in brightness. I had the dude change the voltage reg a second time to no avail. I've cleaned the two grounds on the front of the block as well as the cables at the batteries, hot and ground. I put a meter on the truck and it spikes to around 15.5-16v before settling in the 13.8 range. Any help on diagnosing would be appreciated. I'm still thinking the voltage reg is not compatible or something along those lines. I did not notice the truck doing this pre-alternator rebuild. Thanks.

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Posted by bayou choupique

the banks of bayou choupique

Member since Oct 2014

1818 posts

Posted on 11/20/16 at 8:08 am to White Bear

Not familiar with this vehicle but it does sound like the regulator. Try searching on a ford forum.

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Posted by MikeTh3Tiger

Mandeville, La

Member since May 2013

289 posts

Posted on 11/20/16 at 1:33 pm to White Bear

Can you try a different alternator to see if that fixes the problem? I drive the same truck and have never seen voltages over 14-14.5v.

Also, try posting this question over HERE (Ford-Truck Enthusiasts 99-03 7.3L Forum)

This post was edited on 11/20/16 at 1:36 pm

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Posted by White Bear

Yonnygo

Member since Jul 2014

13887 posts

Posted on 11/21/16 at 8:08 am to MikeTh3Tiger

Thanks guys. I replaced with a new alt and it fixed the issue. I guess it's possible rebuild dude messed something up - but I'm betting it's in the voltage reg though. I burnt google up - it's not a common issue.

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Posted by FishinTygah84

Member since Dec 2013

1976 posts

Posted on 11/21/16 at 8:34 am to White Bear

I had an 03 7.3 and had my alternator rebuilt as well. I started noticing the same exact thing happening to me. After about a week, my radio and dash lights cut off while i was driving. Took it back in the next day and one of my new batteries had burnt up as well as some fuses. Changed all that out along with the alternator and fixed my issues as well. Crazy. I sold that truck in january of this year and got an F150. Not a morning goes by i don't regret that decision. Keep that truck as long as you can.

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