volts

[Teds89IROC]

so I'm getting 12.86 volts from the battery when the car is off and 14.3-14.6 when it's running. As soon as I put on the parking lights the volts drop to 13.3, put on the headlights and they drop to 12.8ish, put on the flashers in addition to the other lights and I'm at like 12.2. The battery was bought 2/05 reconditioned, could it be possible the battery isn't holding charge while accessories are on? I hear the alternator working harder while the flashers are on and my interior lights dim with the flashes. Any thoughts?

[BonzoHansen]

Alternator, grounds, wiring are all possible culprits. I actually think your batttery is fine by your description.

Are you running different sized pullies?

[Teds89IROC]

just the crank pulley. I tried a new alternator and the one I have is actually pushing a little more volts when the car is running

[BonzoHansen]

Does the voltage improve when you bring the idle higher, say 2500? Your pulley may be doing it. Underdrive pullies can be more trouble then they are worth.

[Teds89IROC]

Yes, the volts do improve when rpm's are higher, you can see the headlights get brighter instantly. I thought as long as the alternator pulley was left stock it should be fine.

[jamessr]

I've owned two 3rd gens and yes the stock set is fine. Also do you have the correct alternator in place? I've met a few people who had 90 amps when it takes like 120 amp alternator. Just something to check. Voltage and amps go hand in hand.

[BonzoHansen]

Originally Posted by Teds89IROC

Yes, the volts do improve when rpm's are higher, you can see the headlights get brighter instantly. I thought as long as the alternator pulley was left stock it should be fine.

Still got the stock pulley? If so, put it back on and see if it gets better. Shouldn't take more then 30 minutes.

[Teds89IROC]

It has a powermaster alternator, I believe it's a 140 amp. I still have the stock crank pulley, I'll try that next.

[BonzoHansen]

It's wired normally, right, not a 1-wire job?

[dxdenis02]

high output alternators have a funny output curve... at idle and near idle they actually produce less voltage then stock.... its not until high rpms does it outperform stock.... that coupled with you under-drive crank... is why your getting what your getting.... if you must keep this current set up i would suggest and over-drive pulley for the alternator

[qwikz28]

Originally Posted by dxdenis02

high output alternators have a funny output curve... at idle and near idle they actually produce less voltage then stock.... its not until high rpms does it outperform stock.... that coupled with you under-drive crank... is why your getting what your getting.... if you must keep this current set up i would suggest and over-drive pulley for the alternator

this is not neccessarily true. my powermaster produces more output at idle than my stocker did at max. but you are right in some instances though

[BonzoHansen]

Originally Posted by dxdenis02

.... if you must keep this current set up i would suggest and over-drive pulley for the alternator

..or just get that stock crank pully back on...

[its Jeanne-Marie]

I checked volts with the car running with both alternators and the powermaster does produce more at idle than the stock replacement. Also, the powermaster is a direct replacement, I did not have to run any different wiring. I have another pulley for the alternator that came with the set of underdrive pulley's, which I believe is smaller than stock. I'm guessing that that should balance out the underdrive crank pulley?

~Ted

[BonzoHansen]

Maybe. Smaller makes sense. Change that or put the stock crank back.

[ZeroCool8891]

it could be a fuse i remeber in my firebird it was doing the same thing and there was a blown fuse charged it and was good to go

[Teds89IROC]

well that alt. pulley is actually a tad bigger than stock, so forget that. I was able to fix one of the wires coming off the battery that was getting hot; turns out my idea of adding an inline fuse was actually creating resistance, melting the fuse. I also found a ground wire off the battery getting extremely hot caused by two different size wires. I'll have to check all fuses again. All these things seem to be helping; I want to upgrade to thicker ground wires (part of the "big 3" on TGO) and see how things are. I'm sure it is that crank pulley but as long as I know it's not a serious problem than it doesn't bother me too much. After I upgrade ground wires and check fuses if the problem is still the same I'll change that crank pulley.

[qwikz28]

wait ted, have you ever heard of the big 3?

[Teds89IROC]

I've read about it on TGO..upgrading the two main ground lines and the battery to alt. line. I already have a 4 guage wire going from the battery to the alternator.

[qwikz28]

i'm not saying this will solve you're problem, but at least do it while you're jabbing at the electrical system

[BonzoHansen]

IIRC, here is how my car is wired. I created a few central distribution points (one seen here), and used ford type starter solenoid, so basically there are no wires to the starter but the normally dead positive cable. Big battery cables and very good grounds are key to good system performance. Star washers for all grounds, solid connections (i.e. no crimp jobs) are also a good idea. Those negative cables you buy with the strand of 12g hanging off it? No good.

If I start loading up the electronics, bigger wire would probably be needed from the BAT terminal on the alt, but then I can’t use a fusible link and I’d have to come up with an appropriate way to protect the circuit. Other then that, I’d be ok as long as I run new power circuits off that point.

Where does the BAT terminal wire run on 3rd gens? I don’t remember anymore.