Overcharging after alternator rebuild and new belts?

[LastFbody]

Finally fixed my gimpy gen 2 that was either not charging or barely charging my rear battery. Which great, no more dimly glowing gen 2 light. But now that its fixed the voltmeter is reading in the low red. Worth noting I did give the rear battery a 1 hr charge at one point.



Does the voltmeter read overall charge of the batteries, or just how much the alts are charging?

 

[jnlperformance]

it should be reading the charge rate of the 24v gen. did you replace (or inspect, clean and reman) the shaft brush assembly when doing the rebuild? on the 24v side its what supplies the 12v from gen1 to the ground on gen2 which creates the 24v system. the shaft brush is one of those easy to overlook items.

is it over charging or under? i would start with a newer / better more calibrated gauge before I started ripping it back apart.

 

[tennmogger]

You really should put a good meter on the batteries and see what actual voltage is. Dash meters are 'estimates' of voltage

 

[jnlperformance]

putting meter to batteries does not test alternator / generator charging. bypass batteries, meter each gen individually. youll get actual charge rates. read amps and voltage. 27si should output 80-100 amps depending on stock or remanned with some mods. both are 12v gens. to check 24v check pass alternator.

check generator posts, not batteries...

 

[jnlperformance]

driver side generator at idle should read 14v

pass side should read 14v @ ground / 12v post AND 26v @ 24v post...

all while running @ idle

 

[LastFbody]

With the motor running it was 14.6 at the rear battery and 14.88 at the front battery. Both passed whatever automated charging system test they use at vato zone. Seems high to me, but maybe not dangerously high. Especially considering the driver side alt must have been running that high since ive had the truck, i never messed with it other than throwing a new belt on it. Its possible my idle is too high due to (i think) the previous owner dinking around with the ip.

Ill test it at the alts tomorrow with my buddy's multimeter, thats a piece of equipment I really need to get..

 

[MarcusOReallyus]

it should be reading the charge rate of the 24v gen.

Voltage meters measure voltage, not charge rate. Charging operations can be inferred from voltage readings, but it's still a voltage reading, not a charge rate.

You really should put a good meter on the batteries and see what actual voltage is. Dash meters are 'estimates' of voltage

Yep.

With the motor running it was 14.6 at the rear battery and 14.88 at the front battery. ...

Ill test it at the alts tomorrow with my buddy's multimeter, thats a piece of equipment I really need to get..

Your readings are fine. A passable DMM is less than the price of a tank of diesel. It's about as essential as a socket set.

 

[LastFbody]

I think youre right. I dug around a bunch of old threads (which is unreliable on s.s., half of the links are 404'd from age..) and the consensus from several longtime cucv owners is im within normal operating range. My measurements today returned 14.71v from each alt on the dot.

Either my stock voltage gauge is a little screwy or they werent any good in the first place.

Any recommendations on good aftermarket replacements?

 

[MarcusOReallyus]

Either my stock voltage gauge is a little screwy or they werent any good in the first place.

Or both!

There are some nice digital gauges on Amazon. You could put one on each battery and mount them on your dash next to the stock gauge. Leave the stock gauge in place.

Don't get blue - messes with your night vision.

 

[llong66]

Not to hijack the OPs thread, but Marcus, I changed out all of my interior lights with blue and LOVE it, it seems to me that it is less of a distraction. I had gone w red, then when I got my dome light (one of the ones out of an APC), it has the blue filter on the default bulb and tried switching the rest of mine over to blue....no looking back, least for me.

 

[Tinstar]

ISSOPRO and VDO both make excellent 24v gauges that are plug and play.

Seeing actual numbers on gauge is much better than guessing with the stock one.

My Alternator numbers are almost same as yours.
No issues in over a year.

 

[The FLU farm]

Not to hijack the OPs thread, but Marcus, I changed out all of my interior lights with blue and LOVE it, it seems to me that it is less of a distraction. I had gone w red, then when I got my dome light (one of the ones out of an APC), it has the blue filter on the default bulb and tried switching the rest of mine over to blue....no looking back, least for me.

As I recall, blue light affects night vision the most, yet isn't necessarily easy to see. Which supposedly was the reason for emergency vehicles starting to use blue beacons during the war in Europe.
Red would be my first choice, based on night vision.

 

[MarcusOReallyus]

ISSOPRO and VDO both make excellent 24v gauges that are plug and play.

Seeing actual numbers on gauge is much better than guessing with the stock one.

I agree that's the best option!

 

[LastFbody]

ISSOPRO and VDO both make excellent 24v gauges that are plug and play.

Seeing actual numbers on gauge is much better than guessing with the stock one.

My Alternator numbers are almost same as yours.
No issues in over a year.

Thats sexy. Plug and play is probably for the best, I suck with doing electronic modifications.

It was actually one of your old posts that helped confirm to me my alts are operating at a safe level.