Hey folks, Im hoping someone can help me. Im getting big drops in my stock volt gauge only under load (when I getting on the gas). I really only see it at night when my headlights, fog lights are on. I can actually see the gauge drop fast. Once im out of the gas it goes right back to normal (strong). I just installed a high volt alternator and yellow top battery. I know my efans draw some pretty good current. Any ideas ????

my setup
stereo & Ipod with amp , sub
efans
installed GM fog loghts
high output alternator
yellow top battery

 

did you try an alternator mod?
Adding another 10gauge from the + on the battery to the back of the alt.

 

enlighten me, im not sure what you are talking about. But do appreciate your input greatly

 

I pretty much just said exactly what to do. When you add a system, your increasing the draw off of the battery. This mod helps increase the flow between the alternator and the battery.
There should already be 1 wire running from the alternator to the battery. Just add in another wire.
It's called the Big 3. There's 2 more wires you can add in as well that should help.

See this thread.
https://www.performancetrucks.net/fo...alternator+mod

Looks like 4 gauge is the smallest you want for this. I was thinking 10 gauge for something else.

 

excellent, thx
summary of thread.

add 3 4guage wires
a: 1 wire going from alternator to positive post of battery (better with fuse)
b: add additional ground from negative post to body
c: add one more ground from alternator bracket to body

 

You can add. or go bigger and just replace.

 

ok, so remove existing wire from alternator to (i guess redbox). Then install new wire from alternator to battery. So end up with only one fused wire from alternator to directly to battery. I'll post some good pictures of my finally product

 

Yeah, increase the size of the wire as well.


But, I bet it won't work. If you "just" installed the alt and now have the problem I'd goto guess your alt has a bad regulator. Defective unit I am guessing.

If it is not your regulator and the upgraded wire doesn't fix it...I will become VERY interested in your problem as I suffer from the same problem except mine is only at 5K RPM and higher. Please keep us posted.

 

sounds like we have same issue. have you already tried the big3 fix ?

 

1) alternator positive to battery positive....YES
2) battery negative to chassis...SORTA, I have large grounds going to studs on firewall to provide a separate solid ground inside of vehicle and grounds for extra items under hood
3) engine ground to chassis...NO

I have an amp, but it's nothing special. I do have alot of relays and what not, but I don't feel what I have is a drag on anything in the electrical system. BUT, I have been inside my electrical time and time again, I may have screwed something up myself, but I am at a loss, I am on my 3rd alt and second battery so I just don't know what it could be on mine. Yours sounds like a regulator issue. If you are in park and you rev the gas what does you volts do?