Mustang battery light problem?

Question

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2001 mustang gt 56k miles

please read the last post to catch you up on my problem.

http://www.mustangforums.com/forum/s...d.php?t=475568

well, i got a alternator and battery, went home and strapped them on.

and fired it up, as expected it started(battery has juice since it's new)

and i lowerd the windows and the volatge gauge lowered....again.

same thing when i turned on the ac/ cd player/ ect. ect.

so, i decided to drive it around on two little short trips, and the light stayed on, and the guage still dances around when i lower the windows all the way or press the breaks.

so, this morning, i noticed that the gauge drops alot when i ride or press the brakes,

so i started thinking i have a short somewhere, but as i am driving i was going around 45 and went in to a little dip type thing in the road,(sorta like a steep drive way) my car scraped a bit and as soon as i heard it scrape the battery light went off and the gauge went back to normal, so i lowered the window and pressed the brakes and nothing, the gauge stayed in it's proper position.

so i started thinking, i have a very steep drive way at home, i scrape the bottom of my car no matter the angle i hit it at. i think the driveway caused this,

but, what is under the car that would cause my battery gauge to do that????

is there any main power wires down there or anyhing?????

i am lost.........

i am already $300 in the hole. and i dont have money to be blowing like that, i live on my own and go to school and work fulltime and i need my mustang

Answer 1

well when you might wanna make sure you got the right alternator, and make sure your battery cables are nice and tightly conected to the battery. then trace your positive and negative cable from your batterry and check for any cuts or lacerations in the cables

Answer 2

it sounds to me as well like you have a short somewhere in the car. your first step to finding it is to check and make sure everything electrical works fine, if you find something that isnt working right like a blinker  or a stoplight than that is mostlikely where the problem is, just trace the wires and you will probably find a break in the wire somewhere.

Answer 3

are battery cables clean and tight [both ends]

2 is it correct alternator?  

3 do you have "performance" pulleys?

4.bad voltage regulator?

5 gage should go down while using a elect device..

6 test Alt? should put out 14+ volts..if not...its NG...

6 belt tight

Answer 4

That's a tough one. I don't think it's anything scraping but I certainly see how you arrived at that conclusion. First of all, it sounds like your car scrapes pretty easily. Is it lowered? Most American cars have a lot of clearance above the top of the wheels. Bottoming and scraping is a strict no-no for the chassis engineers. Anyway, if it is something scraping, you need to get the car on a lift. Don't climb under a jacked up car. When it's on the lift, you need a strong light. There are only so many things that can scrape so whatever is scraping should b visible under the car. I actually think something is loose and is being jarred into and out of it's connection. I don't know of an easy way to check this other than while someone watches the battery light, someone reaches under the dash and hood and firmly moves any visible wiring harnesses. It could be a loose ground as well, but that's a pretty new car to have that problem unless it's been in a crash and repaired. I would concentrate on any harnesses coming off the alternator  and in that general area. Again, just give the harnesses a good shake and see what happens. I know that sounds lame. Sorry.