voltage question?

[tims 86]

i have a question about my voltage, i just installed a pa performance 130 amp alternator and wire upgrade kit. also did the contour fan setup the same time. i have plenty of voltage when driving but at a idle it surges up and down. is this normal for this setup? also i have the flexalite 60-100 vs controller. thanks

 

[jrichker]

Check your ground. It is the return path for electricity produced by the alternator.

Any car that has a 3G or high output current alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects. The 3G has a 130 amp capacity, so you wire the power side with 4 gauge wire. It stands to reason that the ground side handles just as much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery , computer, & extra 3G alternator ground wire as described above in paragraph 2. A screwdriver points to the bolt that is the common ground point.

The battery common ground is a 10 gauge pigtail with the computer ground attached to it.
Picture courtesy timewarped1972

Correct negative battery ground cable.

 

[tims 86]

so do i need to add a 4 wire from batt to frame?

 

[jrichker]

so do i need to add a 4 wire from batt to frame?

The 4 gauge ground wire goes from the engine block to the body. Use the common ground point as shown in the picture. The best place to attach the ground on the engine block is where the battery ground attaches to the block.

 

[tims 86]

sounds good i will give it a try.

 

[f8tlfiveo]

Make sure you are using a good gauge and/or voltmeter to check this. My gauge says the voltage is surging and low sometimes but it's not.