What's up guys, I have a tech question. My voltage slightly drops during idle, I don't have a volt meter. I just know it's dropping, cause I can see my headlights slightly dimming. When I rev it up, the voltage seems normal. Anybody know what's causing this? Oh, by the way, I have a new battery in my car.

ThX

 

do you have an aftermarket alternator pully this would be one reason also honda alternators aren't supposed to really charge at idle

 

Actual, I do. So do you think this is the reason why the voltage is slightly dropping?

ThX

 

Underdrive pulleys make the alternator turn a bit slower than stock. So if Honda designed it to just barely keep up with the load at idle, then now at idle it will drop voltage. My GS-R does that with stock pulleys if I have the headlights & vent fan all turned on.

Most people spend plenty of time above 1000rpm to keep the battery charged. If all you ever do is idle, then you shouldn't use an underdrive pulley.

 

[QUOTE]
Underdrive pulleys make the alternator turn a bit slower than stock.

I didn't know that about the honda alternator's.
I appreciate the info.

Much ThX!

 

That's how they make power Less alternator spins = less drag on the engine.

 

I just replaced my Unorthodox alternator pulley with my stock one because my car was dying when I would roll the window down or open the sunroof. Idles way better now.