power loss from alternator?

**DemonSpeed** · 03-11-2010, 08:21 PM

Ok I was wondering if my alt. is not working at 100% how it would affect performance. Since I have a racetronix fuel pump wired off of the alt. it should cut my power some if its not working right correct? I ask this because my car sometimes feels ok, sometimes feels like a rocket and I have noticed that my lights dim when im slowing down and the car downshifts and my volts go from about 3/4 to almost half from a ten min. drive. I should also mention that I have swapped in an ls6, do I need a bigger alt.? I thought i read somewhere that the z06's alt puts out more amps. I also have a red top optima. Sorry for the long post guys

**bigrondownhiller** · 03-12-2010, 01:43 PM

If you need constant power you should run it off the battery and not the alternator. It could be affecting the way the car runs. Did you put a voltmeter on the alternator? Should be putting out around 13.5 volts. Check at the alternator and the battery. Should be minimal difference between the two. another thing to check is all of your connections. Could have some corrosion.

**DaddySS** · 03-12-2010, 03:53 PM

I don't know how much amperage the racetronix pump draws but it shouldn't be enough to impact your charging system. Your battery should remain between 13.2 and 14.5 volts and the light should not dim. First step with charging system checkout is to clean and tighten all the connections, and while the positve cable to the alternator is from the battery, you should run the pump off the fuse panel, not the alternator. The f-body oem alternator is 102 amps, the C5s are either 110 or 130 depending on version. Before trying to install a vette alternator, (102 amps should be plenty for most cases) clean and tighten all connections and rewire the racetronix to the fuse panel.

**DemonSpeed** · 03-12-2010, 07:02 PM

i was told by racetronix and others that running off of the alt. would give constant voltage, is this not right? Also is there anything about the ls6 that draws more amps than the ls1 or is the vette alt. bigger for other reasons. Thinking maybe a combination of the fuel pump and ls6 would be enough to affect it? thanks guys, ill check the voltage.

**Cutlass** · 03-13-2010, 03:17 AM

Originally Posted by DemonSpeed

Also is there anything about the ls6 that draws more amps than the ls1 or is the vette alt. bigger for other reasons.

no vette alt is probably bigger for another reason

**bigrondownhiller** · 03-13-2010, 06:19 AM

Originally Posted by DemonSpeed

i was told by racetronix and others that running off of the alt. would give constant voltage, is this not right? Also is there anything about the ls6 that draws more amps than the ls1 or is the vette alt. bigger for other reasons. Thinking maybe a combination of the fuel pump and ls6 would be enough to affect it? thanks guys, ill check the voltage.

The alternator maintains the battery. Anytime you power something you should always go to the battery or fuse block. LS6 shouldnt draw more amps. The vette might have a more powerful alternator due to other draws in a vette. If you move the power to the battery you should be fine just as long as the alternator is working good.

**Spaz** · 03-13-2010, 07:35 AM

Originally Posted by DemonSpeed

Ok I was wondering if my alt. is not working at 100% how it would affect performance. Since I have a racetronix fuel pump wired off of the alt. it should cut my power some if its not working right correct? I ask this because my car sometimes feels ok, sometimes feels like a rocket and I have noticed that my lights dim when im slowing down and the car downshifts and my volts go from about 3/4 to almost half from a ten min. drive. I should also mention that I have swapped in an ls6, do I need a bigger alt.? I thought i read somewhere that the z06's alt puts out more amps. I also have a red top optima. Sorry for the long post guys

i would have wired it to the battery... i'm pretty sure you can use the post on the drivers side also...

i also have a LS6 swap and have been fine with my alternator (with the exception of my power steering peeing all over it)...

**cammed goat** · 03-13-2010, 03:18 PM

Factory alt isn't up to the added accessory.

**JayTA98** · 03-13-2010, 04:47 PM

I have to agree with all the guys here. Check the connections 1st. In my case I had another different problem that resolved in replacing all the main charging system wires. I noticed right away that my voltage increased and my lights don't dim anymore. I'm not saying swap the wires but if anything else fails and nothing is making sense you can try that. I had a post on my whole story of it but I can't remember the name of it. Good luck