Alternator charging too much?

[454cid]

what year is your truck
95/96 trucks got a cs130d and 99 got ad230 and both of those alternators have more intelligent internal "brains" and also how are your charge cables. if your charge wire is really resistive, your cable connections are corroded, you could be putting out juice because its fighting voltage drop somewhere or the "demand" is causing a need to output depending on how things are

I've never heard if any gmt-400 getting an ad230. The bigger alternator for our trucks is the cs144.

 

[AuroraGirl]

I've never heard if any gmt-400 getting an ad230. The bigger alternator for our trucks is the cs144.

ad230 isnt bigger than cs130d. infact, its behavior is very similar and its charging has the same output charge curve factory. but the electronics on it are improved and it cools better. Edit: my bad the idle output I do believe was marginally improved for them but im less sure of that atm, it may have been same
cs144 also had a cs144d variant.

The 1999 model year is a car thing, it may not have been trucks.

the ad230 is as easy to swap back to a gmt400 as unplugging this

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from a CS130D or CS144D (AD244 replaced the CS144D)

The 1988 to 199_ of GMT would have used this connector at first:

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which also likely had an external fan(the cs130d and ad230 dont use an external fan)