Twisted

I know it is normal for the voltage to drop at idle. It's just that it drops to the line right below halfway on the stock guage. At cruise, the needle is on the line above the halfway mark. (At least, I think there's a halfway mark). Is this normal?

house302

yes it is, its a mustang thing or should i a factory guage thing cause i have an aftermarket guage and it does not do that anymore also if u can upgrade your alternator that will help to. best bet get a new guage

lookinforastang

my guage does it too man

its usually if i hit the brakes or something it will drop for like .2 seconds then come up and maybe drop again. its pretty rapid and i dont even pay attention to it cause the lights dont dim or anything like they normaly would if u had a voltage issue.

2 kwik

I would get a set of REAL gauges

Twisted

Thanks for the replies, fellas. But the guage appears to work well. The car just seems to put out low voltage when the idle falls to 750 (the headlights and interior lights dim).

r.barn

It's mostly from the POS 75amp alternator

they dont charge worth a damn at idle

2 kwik

you can however use the pulley off a 93 cobra alt..as it's a tab smaller and will rid this problem..I lot cheaper than a 3g

Foofighter2585

Common problem caused by adding underdrive pully's. Stock cars are fine with the 75amp, but once you add underdrives it will
discharge at idle. Esp. if you add mods that need more power (Stereo sys., Electric fan, Ignition Sys, etc.)

I'd recommend to anyone adding underdrives to put in an alternator that produces at least 130amp.

Buy adding underdrives to a stock alternator you limit its output by at least 8% to a total of 69amps.

r.barn

I'm about to order this bad boy...... Great price too.

http://verizonsupersite.com/4alterst...g&catuid=10013

gambit90lx

yeah i had the same problem with the factory alt......then went with the jegs 100amp 1-wire alternator......i dont have that problem anymore....