Battery is dead after pulley install?!?
 

I finally got the chance to get my pulleys on the stang. I only changed the water pump pulley and the crank pulley. I DID NOT change the alternator pulley. Now, when I start the car, the battery gauge shows the volts in the red and shortly after, the battery dies. Even when I give it gas, it seems like the battery doesn't charge up. I just bought the battery last september so it should still be fine.

I was planning on buying a 140 amp alternator and then putting the aftermarket pulley on it. If I do this, will I still have charging problems??

Sounds like your alternator took a dump. The crank pulley alone will affect the alternator, but once the engine revs a little, it should still be charging full bore.

Yea, that sux, your alternator coincedently went out during that time i guess, I have a crank pulley (street) and steeda waterpump pulley, no alternator underdrive pulley, and just saw a little voltage loss, but it clears up when i give it gas, my battery is old too, knock on wood....

I have all three pulleys (March).
It will not charge at idle but immediately comes up to normal as soon as it hits about 900 rpm.
As long as you are not spending alot of time at idle with a high accessory draw, your battery should not go "dead".
I don't think it is your pulleys. The slower speed of the crank pulley could have caused another problem to inadvertantly show up.
Check your alternator, or have the Autozone guys do it for you if you don't have the means.

Thanks for the help guys. I thought that once I drove it, the volts would go back up but they never did. Guess it's time for a new 140 amp alternator! YEA!

I had to replace my alt to a 130 one as well when I got pulleys!

JL1314:

How does the new alternator work?? I mean, if I wanted to replace the sound system down the road sometime, will I have any charging problems?

Instead of 80 amps it pushes 130 amps, so it can keep the charge on the battery alot faster! The stock one can hardly keep up without the pulleys on!

I'm no expert, but I experienced the exact same problem you are having, and if your car is anything like mine, the 140 amp alternator wont fix anything. After I installed my pulleys, one day later the battery was constantly dying on me. So I express ordered a 130 amp alternator. Made the switch, and the problem did not even close to go away. A quick way to check is hook up a voltmeter to your battery. It should read aroudn 14 volts when the car is off and around 12 when the car is on at idle. If you are making 10 or even 11 your battery is not charging properly.

Upon closer analysis, I noticed that the small crankshaft pulley makes your belt spin incredibly slowly, and regardless of how great your alternator is, it just can't spin that alternator fast enough to create the juice needed to power your accessories, and charge your battery, 80 amps, 130, or whatever else.

Another major drawback is your water pump. When using underdrives, your water pump (from my experience) does not turn fast enough to cool off your motor. Sitting in traffic with the AC blasting, I noticed my temperaturue rise slowly, way higher than I'd like it too. After a couple of weeks i was fed up with underdrives, and I figured i'd try and get my 15 horsepower somewhere else.

I trashed the pulleys and bought a blower, which seems to be a little more efficient at the horsepower creating game.

Just my 2 cents.

dino

At idle your battery should be reading no less than 13.5 volts if you want to consider the alternator borderline, even. With the car off, and the surface charge removed a fully charged battery should register around 12.6 volts. A proper charging alternator will charge at about 14.4 volts.

The G3 alternator has a larger pulley than the stock alternator, which creates a sort of underdrive effect right there. The 1993 Cobra had an underdrive crank pulley from the factory, and it charged just fine. It could be a wiring problem, but more than likely, just a crappy regulator or alternator. The 130amp well more than doubles output at idle.

We installed MAC underdrive pullies - our stock 80amp alt was crap prior to pullies. Installed a Flex-a-lite Black Magic electric fan, MAC pullies, and PA-PERFORMANCE 3G 130amp alt(used their pully as it's larger than stock). Everything is working fine with plenty of juice when fan, lights and other accessories on.

My PA-PERFORMANCE alternator is on it's way (ordered monday). Now, will the pulleys supplied on it suffice?? Or should I swap it for the ASP pulley I have?

I would probably leave the pulley on! You should be fine! Check it out, experiment, you might prefer the ASP pulley!

I talked to Rick at PA-PERFORMANCE and he recommended leaving his pulley on as it was about the same size as my MAC pulley. He said you gain very little, if any, hp from the alt pulley - most of the hp gains come from the crank and water pump pullies. He also mentioned that if you take his pulley off and put another on - it'll void the life-time warranty on the alt.

Install on the PA-PERFORMANCE alt was pretty easy, you may have to do a little filing on the alt bracket - as the housing on the 3G 130-amp alts are a little bigger. Are you planning on upgrading to 4g wire on the output side?

Yea, I ordered some new wire with the alternator. I don't plan on really driving until april (damn winter), so if I run into anything else I need, I'll just order it up!

You shouldn't need anything else - take you time with the the connectors and solder the connections before putting new connectors on.

Will do! Thanks for all the help!