Battery possibly altenator?

[karr95]

This past weekend I put new front speakers in my sister's 92 RS. After I was done it started up just fine and she went back to school. She called me yesterday and told me she had to get jumped because the battery took a dump on her. The battery is old and it very well could be the problem, however, I am thinking it is possibly the altenator too. Every now and then at night with the stereo on and the headlights on, the interior lights would go dim until you press the gas. Any thoughts?

She is coming home for Easter so whatever I need to do needs to be done that weekend. As it stands now, I am going to get a new battery and replace the terminals that acctually screw into the battery.

[V]

yeah change the battery to start with and replace/clean the terminals. Once its all together, use a voltmeter to see how much charge there is at the battery while the car is running. it should be a little over 14 volts.
If she got the car jumped and it ran after the cables were removed, i doubt the altenator is the problem, because the car would have died out soon after. Also check to see if a light was left on or something else that could have maybe drained the battery.

[BigAls87Z28]

Exactly what he said. I also doubt that its an alt, but the dimming of the lights could mean that you are putting an excessive load on it. I dont know what else you have done to it, but it most deffinatly is dimming for a reason. Have her watch the amp gauge when she drives. If its below midway, then its running on battery power or close to it. If its north of midway, then you should be ok on the alt, and its just the car that requires a lot of juice. You could upgrade to the police alt that puts out 140. You can get that at most auto parts stores.

[karr95]

The car is a bone stock 92 RS with the 3.1. It was strange that the car started nice and strong on Sunday and on Wednesday the battery is dead. She may have left a light on and didn't tell me. I'll take your advice and see where everything is at. I am definatly gonna replace the terminals and I will go from there.

Thanks!

[IcemanSS]

Heres what I would do. First I would put a new battery in it. Down if she is drawing that much power just from the radio, it's time to in vest ion a power cap. I installed one in my SS after changing to the 1600 watt amp. It's a 1 farard power cap from stinger, and depending on the song and how loud I have does the amp s even move. But it's sounds like a bad cell in the battery. I would go there first. If the terminals are all screwed up , it's a very cheap fix.

[1bad3800]

well as an employee for Autozone, i would say yes replace the battery and terminals first. then check if u see the volt meter in the car like surging when the radio and everything is on.. If thats the case have the alt. looked at. Take it to Autozone if there is one or Advance and they will test it for free.