Alternator charge Problems!

[Fausto]

Whats up guys, I have a big problem with my Yukon. Every time I'm driving it and I let go of the gas, It looks like it wants to turn off and the battery gauge drops below half and goes back up. I changed battery (which needed to be changed anyway), and also changed the alternator. It still does the same thing, my dad said it could be a sensor but who know's. has anyone had this problem before? Thanks

---------- Post added at 04:16 PM ---------- Previous post was at 02:20 PM ----------

Bump

 

[ccapehartusarmyINF.(ret)]

okay first question is what size alternator do you have the stock one i think its either 105 amp or 130 amp and did you upgrade all your wiring under the hood i think they call it "big 3 upgrade" or something stupid like that its upgrading all your charging system wires to 0 guage
its possible your sucking more current then the alternator puts out i have an 02 LS tahoe back when i was only running about 1200 watts rms i had problems i was pulling more current then the alt could put out and it would just take it from the new optima i had bought and i killed the optima in about 6mo i had to get a 250 amp alternator since then ive upgraded i run two amps now at 2500 watts true rms
to run 1000 watts rms you need roughly 70 amps of current at 14 volts and 40 to 60
amps for the vehicle and the stock alt. only puts out 130 amps at like 2000 to 3000 rpm
and 90 amps at idle so its possible your at or over the limit of your charging system
and unless your going to get a bigger alt. dont bother with caps and extra batterys
extra batts with isolater installed is purely for listening to the stereo with your car off plus they add an extra drain on your alt. so do caps

---------- Post added at 04:11 PM ---------- Previous post was at 04:07 PM ----------

now ifyou plan on upgrading your stereo system even further the ultimate solution in my opinion is a 2nd alt basically one runs the vehicle and one runs yer stereo
the problem there is the dual alt kits are like 300 bucks just about everywere ive looked

 

[TxDrewski]

I have had to do this to two trucks, my 02 and the tahoe..

Where the little junction box is, to jump the truck off and the wires connect to a nut, I place 2 to 4 washers behind the nut to bring it further out. So that I get a better connection from the alternator to the positive. I could reach and grab the wires on both trucks and move them, and the voltage would drop. there was too much movement and I had the nut as far as could tighten it. May not help at all but it worked for me

 

[ccapehartusarmyINF.(ret)]

yeah the wire from the alt. to the orange box thats like 8 guage one time the nut inside the orange box got loose causing high resitance and after a few days it caused a section of wire at the pos batt terminal to cook and literally melt most of the sheeth off

 

[TxDrewski]

Luckily I caught mine both times before it got that bad lol. I was driving at night this last time it happened and had to pull over and fix it before the truck died lol.

 

[ccapehartusarmyINF.(ret)]

and before that wire cooked it started acting funny like when i wasnt moving and i turned the wheel id get i big volt drop, holding the break at a stop light it dropped