My 90 EX wouldn't crank the other day and the started sounded weak when starting. I took my battery to get it checked at Autozone. I had purchased the battery in 2006. Battery was diagnosed as bad.

I got a replacement battery and installed it. Now my battery light comes on when I'm driving the car but its weird. The light will come on when I'm on the brakes coming to a stop. When I let go of the brakes and give it some gas, say from a stop or a red light, the battery light turns right off and comes back on the next time I slow to a stop. The car runs and starts strong like a champ so I'm not sure. Also, the alternator was replaced less than 2 years ago with a reman.

I have noticed too that my front passenger side window is really really really slow to move up/down after battery replacement. It was already slow prior to battery replacement but now its glacial. Not sure if that would have anything to do with the battery light coming on during slowing to a stop though.

I'm going to swing by Autozone and have them check the alternator output tomorrow. Just checking to see if anyone here has seen any similar problem.

 

x2 on testing the alt.

Could check all of your power & ground connections as well. Make sure that they are clean and tight. Take a wire brush to the mounting surface and wire connectors. Dirt and corrosion can put a strain on your system.

 

Ghost beat me to it again. Get that alternator tested.

 

I can almost guarantee it's the alternator. The reason the light comes on when you brake is that it has to put out more electricity to power the brake lights(to turn them on), when you take your foot off the break, combined with accelerating = helps the alternator to charge the system. Normally the light coming on when driving = alternator, just my experience.

 

Invest in a $10 multimeter from Sears or Autozone or something. You can perform your own voltage drop tests on various connections instead of having to remove and clean them all. Once you find an unwanted voltage drop you can take care of the problem. It's much quicker and easier that way.

As far as the battery light I would suspect the alternator. Loads change as you brake/accelerate, as mentioned above.

I have encountered strange electrical problems on lots of occasions as a tech. I've seen bad connections that only appeared when turning left. I've seen headlights that come on when you push the brake pedal. I've seen a car lose all of it's backlighting after the owner had the air filter changed.

Point being, check the simple. Once the simple is confirmed ok, suspect the impossible.

 

Thanks all for the advice. I didn't get a chance to swing by Autozone but it sounds like I may be replacing the alt soon, again. I'll update when I find out more. Thanks.

 

This time don't buy Dura-crap. I've had more bad luck than good with their stuff ie: weak brand new starter, low output on a new alternator, brakes that wore out in 1 year. Autozone is always my last choice.

 

most the time those employees don't know how to use the machines anyways. An old trick to test the alternator is to take the positive terminal off while the car is running, if it stalls then it's junk.

 

I took my alt off this am and took it to Autozone. Failed. Free replacement FTMFW!!! Haha, the 'Cord is back on the roh ad. :D

Still have a list of many things to replace though. But I love it so its all good. :D

 

The alternator is one component I think you should not replace unless the diodes are bad or failing which Autozone can test for. Other than the diodes, the regulator and brushes are usually the other components that would fail. When you buy a reman, you don't know how old are the diodes b/c when they rebuild, they just replace either the regulator or the brushes. So you don't know how many miles are on that actual reman alternator. This is why some times you get a few to fail before you could get a good one.