Voltage and Light problem

[forcefed03]

Hey guys, i got a quick question. I have my optimum yellow top in my trunk, and i have a 180amp high output alternator. I checked the voltage at the battery in the back under 1200rpms and it shows around 13.8 - 14.2 volts. Then i go to the Fuse box under the hood and i see around 14.8 - 15.2 volts at around 1200 rpms. So my voltage is fine... wiring is fine.... but what happens is:

At night, when my car is idling, the headlights and the dash lights shine perfectly, but when i touch the gas or start driving everything gets brighter (all lights in the car), then when i get off the gas, everything goes back down....

I called a few places and they said its normal, because when your car is idling its the normal brightness, then when you touch the gas, you spin the alternator faster thus creating more amps/volts, and thus making everything brighter...

Has anyone with a high output alternator experience this? Its VERY annoying because i see every little thing.

What does cure it, is i turn on the A/C and it stays at the low idling brightness even when i touch the gas (drive)... meaning the A/C sucks the extra power making it normal or something...

Anyone know? i can get a quick video of it tonight if you need

 

[wizbangdoodle]

I'm not sure how you are getting more voltage at the fuse box than at the battery. They should be the same.

 

[forcefed03]

I'm not sure how you are getting more voltage at the fuse box than at the battery. They should be the same.

When I was told and I was thinking its because of the high output alternator... outputing a ton of amps, kinda like boosting the power

 

[wizbangdoodle]

Amps won't do anything to increase voltage.

 

[racebronco2]

You losing voltage because you don't have the battery grounded properly.

The reason why your light are getting brighter is because your not spinning the alternator fast enough at idle.

 

[forcefed03]

You losing voltage because you don't have the battery grounded properly.

The reason why your light are getting brighter is because your not spinning the alternator fast enough at idle.

Well i checked it out tonight again, and it gets bright when i touch the gas, and then goes back to normal brightness... so at idle theres normal brightness, then when i hold the gas at 1200rpm the light goes up then back down while im still holding the gas down. so it doesn't stay brighter, it gets brighter then back to normal brightness while holding gas.

I can change the ground, but would that fix the brightness going up then back down while i hold the gas down?

And how is my alternator getting under spinned? its the stock alternator housing and pulley...

thanks man

 

[racebronco2]

I think it's a ground problem. If you have a ohm meter you can check if it is a ground problem. You need to set it on volts. Turn on all your accessories, headlights, radio, fan, a/c etc, do not start the car. With one of the probes on the negative side terminals and the other try at different places that are grounded. If you get anything over .030 you need to add more grounds. When i checked over a year ago i had .027 at the body and .019 at the engine. I did add two more grounds to get these numbers.

 

[forcefed03]

I think it's a ground problem. If you have a ohm meter you can check if it is a ground problem. You need to set it on volts. Turn on all your accessories, headlights, radio, fan, a/c etc, do not start the car. With one of the probes on the negative side terminals and the other try at different places that are grounded. If you get anything over .030 you need to add more grounds. When i checked over a year ago i had .027 at the body and .019 at the engine. I did add two more grounds to get these numbers.

Alright I think you are right. But I only really don't know much when it comes to voltage consistency in a car. But i have a MM subframe in the trunk, and the battery is grounded on one of the bolts securing the subframe in the trunk. Then i have two green bolts on the right side under the hood that is bolted to the body. I can check each of these grounds, but how would i add more grounds?

 

[racebronco2]

You just add more ground from the battery to the frame. At one time i used high quality stereo wire and found that was one of the reasons why my voltage was too high. I switched it out and the voltage dropped alot. I ended up adding two more grounds from the engine to the body. Still not finished, my voltage was .044 at the body and .033 at the engine. I added one more ground from the battery to the body and the body voltage dropped to.019 and the engine volatge dropped to .013 valtage.

 

[forcefed03]

You just add more ground from the battery to the frame. At one time i used high quality stereo wire and found that was one of the reasons why my voltage was too high. I switched it out and the voltage dropped alot. I ended up adding two more grounds from the engine to the body. Still not finished, my voltage was .044 at the body and .033 at the engine. I added one more ground from the battery to the body and the body voltage dropped to.019 and the engine volatge dropped to .013 valtage.

You're a god! I added another ground from the negative terminal on my battery to my strut brace in the back (where the other initial ground is) and it GREATLY reduced the brightness, and the car runs sooo much nicer! its smoother, and just feels great...

On another note, if it does brighten a little bit, but nothing like before... what if i was to add another ground? What could happen if i ground to much? sorry if i sound like newbie lol.

 

[Jimmysidecarr]

You're a god! I added another ground from the negative terminal on my battery to my strut brace in the back (where the other initial ground is) and it GREATLY reduced the brightness, and the car runs sooo much nicer! its smoother, and just feels great...

On another note, if it does brighten a little bit, but nothing like before... what if i was to add another ground? What could happen if i ground to much? sorry if i sound like newbie lol.

The only negative I can think of to adding additional redundant grounds when they might possibly not have much effect, would weight gain.

So I'm thinking ground away.:beer:

 

[TNTLightning]

The only negative I can think of to adding additional redundant grounds when they might possibly not have much effect, would weight gain.

So I'm thinking ground away.:beer:

^^^THis. You're grounded. Now go have fun.:dw:

 

[forcefed03]

^^^THis. You're grounded. Now go have fun.:dw:

about the ground the shit out of my car. thx :banana: