Just upgraded my Alternator. but lights still dim

[87luxsprt]

Can any one give me any thoughts on why my volt gauge still goes crazy when my sound system is playing. I just got a Upgraded Alternator from a local shop who sells high output Alternators. Its a 140 AMPS. My car is a 87 monte carlo luxury sport.

The system is a Alpine deck. Two amps. One is a Kole Audio 3000watt single channel wired to a JL Audio W7 13.5. And a small voice amp powering some 6x9what and some 5 1/2. I have all 0gauge wires. Even when i put on the signal lights the volt meter flickers... any ideas. Thanks

 

[woody31]

check your grounds ,,,, all of them,,,,,, 8)

 

[87luxsprt]

Ill check tomorrow morning. Do u think maybe the battery can be part of the problem. Even when the stereo is off the volts drop everytime i hit the brakes, lights,signals...etc. my battery is like 5 months old. But it does look small. Looks like something from a crappy *ss honda...<-----(Peace of sh*t)... lol

 

[80ELCAMINOFLAKE]

Yes grounds are always first! I just upgraded my alt too to a 105volt CS130 alt... And so far so good... Make sure if u have a aftermarket volt gauge that the ground is grounded by itself, not attached with any other wites, by itself.. Thats the ways i have my set up.. And whEn i turn my key its at 12volts, and at crank doeent go lower than 10 volts, i have a shitty battery myself and dont have that much if a problem, but i am looking into a red top optima..

 

[Bumpin1ohmSS]

check your grounds ,,,, all of them,,,,,, 8)

x's eleventykabillion 8)

Hit autozone up and get a few of their ground and power cables in 4 gauge. Sand down the shiny pretty ends to bare metal. Sometimes they polish em up. We dont care about pretty. We want current flow. Then take a look at ALL your factory grounds and power cables. Clean away any paint, oil, debris and such. Clean up all your bolts, keeper nut, ect that secure the cable end. Upgrade or add to your ground from battery to frame. Upgrade your thin positive wire from the battery to the alt. I had the same prob on my 87 Elco. Man the ground to the alt bracket just popped off in my hand! I cleaned it up, and added two more 4 gauge grounds. No voltage drop or blinking headlights. AND I did a quick half assed job just to see if a difference was made. Youtube "The big 3 Upgrade" It may be overkill to do 0 gauge, but at least 4 gauge and check/clean all your grounds and power cables...

Here's a cool vid explaining things.

[youtube]ASMwuofj9H4[/youtube]

 

[ve3oky]

Very good info and a great video.

 

[olds307 and 403]

A battery with large cranking amps and reserve capacity is a good idea. As said above, double check your grounds. What voltage is it dropping to? I had a problem with a brand new alternator, same thing would drop to battery voltage fully loaded. The battery connection was loose in the case, tightened it. I had to pull apart the alternator but worth it. Now it barely drops at all, even at idle fully loaded.

 

[Longroof79]

Usually with a higher output alternator, you would use a heavier gauge positive cable. I added a 6ga...I think?...cable between battery positive and + lug on the back of the alternator.
Use a multimeter and check your output at the alternator. Should be around 14-14.5 volts.