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Discussion Starter · #1 ·
Been watching the volt gauge fluctuate recently. Checked voltage on batteries at idle when gauge is showing below 1/2 and nothing on, reads 13.4-13.5v. Today, the gauge is reading approx middle and idle voltage was 13.9v. An electrical shop said it could be brushes sticking. It is the original alternator, only 64k miles but almost 19 years old. If I want to change it out, what brands tend to be the best? Are Bosch a quality unit? I have read DB Electrical makes solid units, but they are spendy. Or would it be better to rebuild the one I have?

Thoughts and suggestions?
 

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Discussion Starter · #3 ·
Yep, after GPs shut off. Also, I have driven it a while and pulled in driveway and checked then before shutting off. Truck starts immediately, no problem with low batteries. When first starting, while GPs are on, volt gauge shows very low. Have not measured battery voltage while GPs are on, maybe that is next just to have more info. There are so many alternators out there, hard to know what is decent and what is junk. Rockauto has Bosch as well as Remy. Remy seems to be a popular product on Rockauto. Thoughts?
 

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I went through the same thing and finally decided to rebuild my own rather than trusting an unknown quality refurbished unit. This kit worked great for me. You don't need to change the bearings most likely as they are a real bear, but replace the regulator/brushes and the slip ring and you'll be good to go most likely.
https://alternatorstarterrebuildkits.com/product/3g/
 

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Checked voltage on batteries at idle when gauge is showing below 1/2 and nothing on, reads 13.4-13.5v. Today, the gauge is reading approx middle and idle voltage was 13.9v.
Truck starts immediately, no problem with low batteries.
There's nothing wrong with the alternator - it's a gauge error, probably caused by a weak connection at the film circuit on the back of the cluster. But it could be anywhere between the alternator & gauge.

Start with the DMM probes on the battery POSTS (not the clamps AROUND the posts) (either battery) and keep that voltage reading in mind. Move ONE probe at a time along its circuit ONE connection or component (post to clamp; clamp to cable; cable to ring terminal; ring to starer relay post...) at a time, working your way toward the gauge. When the reading drops, you just crossed the fault.

If it's the film circuit contacts, polish them with a pink eraser or brown paper.

 

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Discussion Starter · #6 ·
Thanks for the possibility Steve. Any tips on getting to the back of the instrument panel? I know, do a search.......
 

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Yeah, pull the cluster. Lol

Sent from my SAMSUNG-SM-G935A using Tapatalk
 

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Read this caption & follow the links in it:

 
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