Am I testing my alternator wrong?

[tylork92 10+ year member]

Do you know what voltage the alt is set to? Usually there is some sort

Of paper work included with the alt that tells.

But your not gonna be able to test full output of the alt until your voltage gets below 13v. Honestly if your starting voltage is 14.03 and your only dropping to 13.8, I don't see a problem

 

[ForceEdge 10+ year member]

Do you know what voltage the alt is set to? Usually there is some sortOf paper work included with the alt that tells.

But your not gonna be able to test full output of the alt until your voltage gets below 13v. Honestly if your starting voltage is 14.03 and your only dropping to 13.8, I don't see a problem

It didn't come with any sheet or any paper work showing how the alt performs. Which I find fishy. My stock alt put out 14.4.. So I just don't get it.

 

[tylork92 10+ year member]

It didn't come with any sheet or any paper work showing how the alt performs. Which I find fishy. My stock alt put out 14.4.. So I just don't get it.

not all alts are calibrated to put out 14.4. i dont really understand why but there not. may have something to do with the higher output conflicting with the cars ECU or something. My Mechman usually charges charges around 14.2 during normal weather conditions. However, in colder temps i wills see 14.5-14.7 until motor bay warms up.

 

[ForceEdge 10+ year member]

not all alts are calibrated to put out 14.4. i dont really understand why but there not. may have something to do with the higher output conflicting with the cars ECU or something. My Mechman usually charges charges around 14.2 during normal weather conditions. However, in colder temps i wills see 14.5-14.7 until motor bay warms up.

Hmm. Well I don't know it just seems odd that it drops to 13.8-13.9 at 2k rpm with just all my accessories on. Seems a little weird

I feel I shouldn't drop that much at all. Maybe it has something to do with my car? Is an external voltage regulator my only route along with testing it?

 

[phemps 10+ year member]

Its been said a couple times but ill mention it again because i don't think you addressed it, but definitely make sure your belt is not slipping. that could possibly be contributing to the voltage drop under a load. I know i had that problem with an alt swap. smaller pulleys of course

 

[bhsdriller 10+ year member]

tried contacting dc about it?....what did they say

 

[sexy 10+ year member]

The way an alternator works has already been explained in the other thread this guy started. It’s the same as a home generator and if you ever listened to a home unit or the engine in your car you will hear the engine lug down when a demand is put on the generator or alternator. You then have lag time. That lag time is where you will see a slight drop in voltage while the power supply (alternator) tries to meet the demand. I have three high output alternators under my hood but it would not mater if I had twenty of them I would still have lag time. This is such a simple thing to understand that I could explain it to my wife and she would understand it. LAG TIME = voltage drop

Go listen to any power generator and you will hear it. Use a volt meter and you will see it.