hey guys Im just wondering what can it be when,..your in a light or in a stop with your a/c on,..and suddenly the battery gauge needle goes from being in H to L,..which in my indications means low battey...but I already checked the battery and its charged,..and the alternator is working fine I have test it already...is there any fuse I should check or what do you all think??

 

I would check for an internittent overcharge condition from the voltage regulator.

 

Can you post some info on your truck or complete your profile.

 

Do you have electric fans?

 

It's an 07 saleen supercharged, electric fans, troyer performance fuel pumps, not a big system just one 10' speaker, electric water pump, and that's the only thing I can remember, that need battery, I know it's alot of electricity but I have an optima battery red top, rated: CA 1000 CCA 800 RC 100

 

see if the drop in voltage coincides with the fans coming on. Most fans draw alot more than what they claim. those fans should kick on with the A/C. Now you have the high draw of the A/C and another 60 amps or so when the fans come on too. Do you have UDP's?

 

No i dont have UDP but I checked the alternator and theres a bad diode, I'm thinking of getting a 130amp alternator and replace my 110amp, but still undecided