1999 grand am Problems

I have a 99 GA and am having electrical problems i recently had to replace the alternator and battery, and that corrected the problem for a short period of time, when i replaced the alternator the hareness broke and i had to replace it, im not sure if i wired it right ,the car has ran for about 3 months and now im having the same problems all the dash lights come on gauges stop working and shortly after that the car will die and wont start again without a jump. Any help would be greatly appreciated and wiring diagrams would be great too.

Welcome to AF.

I would check the battery cables make sure they are clean and tight. Also check the ground wire where it bolts to the engine/trans area, jsut follow the black wire you'll see the end.

I might have a pic of the wire harness & plug thing.
Is that what you replaced , the wire harness and plug ?

Also, check the voltage with the engine running. If you've got aftermarket accessories that draw too many amps, you probably burned up the alternator again. You'll want to buy a high-amperage alternator if this is the case, an alternator that is too small will keep failing.

Thank you for the responces, i have checked all grounds, put new cables on, cable ends, i replaced the plug that goes into the alternator, only problem is that the new plug had plain white wires to splice in, and the wires are colored comming from the battery/fuse box.

Thank you for the responces, i have checked all grounds, put new cables on, cable ends, i replaced the plug that goes into the alternator, only problem is that the new plug had plain white wires to splice in, and the wires are colored comming from the battery/fuse box.

The color really makes no difference electrically, it just makes the wires easier to follow through the vehicle. I have no idea what color the wires are on yours, but if you hold the old connector next to the new one with the same side facing up, lets say the wire colors left to right are blue, red, and orange. Put the new left white wire to the blue wire, the middle wire to red, and the right wire to orange. If it makes it easier, take a marker or colored tape and mark the white wires.

I dont know where the wires were placed in the old connector, the whole connector broke when i removed the alternator the first time, I have tried all combonations of wires.

I have pictures of the wiring but i cant seem to post them...

I dont know where the wires were placed in the old connector, the whole connector broke when i removed the alternator the first time, I have tried all combonations of wires.

Connecting the wrong wires may have damaged something. I'm not sure about the alternator on your vehicle, but my '98 with the 2.4L is controlled by the PCM. Yoiu might have fried something inside the alternator if you ran constant power to the field terminal. Driving down the road, it should have a very low pulse width to the field wire, probably somewhere around 10-30%. Even at idle without much electrical load it wouldn't ever reach 100%, the computer will not command more than 90%. Running at 100% would have almost certainly put your system voltage WAY too high, and might have taken out the alternator. I'd have the alternator tested before you go any further, and be absolutely sure about your wiring before you connect it.

To post an image, you have to upload it to an external host. I use photobucket, but I'm sure there are hundreds of free sites. From there, click on the insert image and put in the URL of you pictures.

Cut those butt-connectors out of there and solder and heat-shrink those wires! Honestly, I wouldn't be supprised if those were causing the problem after 3 months of corrosion building up in there.

I will do that, im just waiting until i find out if i have it wired right. those butt connectors are only a few days old and the were taped up before the pic. now im really lost, i charged the battery connected the negative cable and left the positive off and the battery was dead a day later.

Possibly case-draw. Put a voltmeter probe on one terminal and touch the battery case near (but not touching) the other terminal. If there is any voltage at all, clean the case with baking soda and water. The worst case-draw I've ever seen took 3 days to go dead, and that was an old visibly dirty battery.

Otherwise, it has to be a bad battery.

That thought had crossed my mind about case draw, the battery and alt. are brand new, less than a week old.

If you dont have the wires connected right you'll have problems.

If you need a wire diagram for this let me know and I'll post it .

If it's that new and went dead, it's gotta be a bad battery... with only one cable connected to it there can't possibly be an external draw.

Xero, it sounds like a picture of the electrical connector into the alternator could help him out, or just the order of the wire colors. I was gonna take a cell phone pic today, but as common as they are, we didn't have a single 3.1/3.4L GM in the parking lot!

A diagram would be GREAT Xero, thank you. Could my starter be killin my battery?

A diagram would be GREAT Xero, thank you. Could my starter be killin my battery?

I actualy uploaded the diagram lastnight heres the link. :D
http://www.automotiveforums.com/vbulletin/showthread.php?goto=newpost&t=912158

Well if the wires are crossed it can burn up battery, alternator, or possibley damage the PCM/BCM.

Hope that diagram helps. :thumbsup:

Thank You very much for all your help guys. I appreciate it. I do have the wires crossed. Im going to correct everything and I'll let you know what happens.