Well, a few days ago I noticed that my lights were flickering and my battery gauge was lower than normal. The next day it was fine. Then today the battery level was almost on red. I noticed that when the turn signal blinks the battery gauge shows a loss of power and when it turns off, power goes back up. I also noticed that my turn signals blink slower when my lights are on thean when the lights are off.

I thought that this was the alternator so I went and got a new one and installed it. To my surprise, I still had the same problem. I can't think of anything that could cause this type of problem other than a bad alternator. I am thinking that I could have got a bad alternator. I am taking the old one in to have it tested in hopes of finding out if it was the original problem or not.

Is there anything other than the alternator that could cause this problem? Thanks

 

1. do you have any sound system in it amps subs anything out of the original that might be draining the battery

2. does it feel shakey when the car is stoped like at a red light

 

Sounds like a bad ground or power wire to me. Double check your battery ground wire as well as the ground wire that goes from the back of the passenger side cylinder head to the chassis. Wiring becomes a common problem as these cars get older and a common upgrade includes 1. replacing the wire to the back of the alternator with a larger gauge wire, 2. replacing the ground wire from the cylinder head to the chassis with a larger gauge wire, and 3. removing the battery ground from the block and grounding the battery directly to the chassis. Another option for #3 is just leaving the battery ground attached to the block and adding a second large gauge wire that goes from the battery directly to the chassis. Those 3 upgrades will actually boost your grounds and power to your accessories and engine and make things run a whole lot smoother.

 

first thing I would check is corrosion on your battery terminals but I have purchased 3 new alts that were bad from the start before. Also the first two of those did test bad on the parts store's test machine but the third tested fine. went and purchased and alt from a different store(advanceauto)and problem solved and their tester indicated the third alt was bad as their tester had one voltage test indicator on it that the first store did not have(Auto Zone)
But that was 7 years ago so maybe they have upgraded since

 

Well, I had my old alternator tested and found that it is actually good, so I am guessing that the alternator is the problem.
I do not have any special sound system, just two 6x9 3-way Pioneers in the back because someone cut the originals out at one point. It doesn't really shake when stopped, runs a little rough sometimes, but not bad.
My car has a ground running from the negative battery cable to the chassis and the one from the back passenger side of the engine to the chassis. I checked the one from the negative battery cable and sanded all the rust/corrosion off of it, which didn't help anything. I also cleaned up all the connections for the alternator. I am going to clean up the ground cable that hooks in just below the alternator and see if that helps, if not I guess I will have to check the last ground wire.

Thanks for the help, hopefully something here will fix it

 

don't rule out the battery if you have a good spare battery you might try using it to see if it solves your problem

 

I cleaned up the cable running from the negative battery cable to the alternator mount as well as the battery terminals/cables. Still no good . Didn't mess with the ground from the back of the engine yet, have to find a good tool to get it off (its a little crammed in there).
Hmm, can a bad battery cause this type of problem? There is a high chance that my battery is going bad since it was made in '02.

Here is a video of what happens: http://www.youtube.com/watch?v=TrtYIOKYaEw

 

looks like a voltage regulator problem. you could try starting the car and then disconnecting one of the leads from the battery to eliminate the battery being the problem but looks like a bad alt. also not sure if there is another regulator external to the alt, may have to do research to see if thats so

 

Honestly I didn't see anything unusual in the video clip you posted on youtube. I saw the voltage needle pulsing with the blinker but my '91 and my '86 have always done that.

If you're noticing the blinker going slower with the lights on then it's very possible that the alternator is not supplying enough current for everything to run. However, don't assume it's the alternator right off. The battery "could" be causing the symptoms and making you think it's the alternator. If your battery is 5 years old, go ahead and replace it. Even if it doesn't fix the problem, that battery is on it's way out soon as old as it is. THEN, if that doesn't fix your problem, take that alternator off and have it tested and see if they'll replace it even if they do "say" that it's good.

Don't bother with trying nhraformula's method to eliminate the battery. Starting the car and removing a battery cable (his suggestion) will NOT eliminate the battery. Once the car is started, it runs off the alternator so by starting the car and removing the battery cable then you're actually eliminating the alternator. If it dies when you remove the battery cable then the alternator is bad. If it stays running, the alternator is fine.

 

86TpiTransAm is right about the pulsing with the turn signal but i didn't realize you had the signal on. He's also right about if the car dies then alt is bad. But it seems as if your problem is intermittent. You stated in original post that one day it is fine and the next your volt gauge is in the red. That is the exact same problem I had when I got three bad alts from Autozone. And like I stated in earlier post the third alt tested fine on their tester but I went ahead and purchased an alt from AdvanceAuto and problem solved. Not saying this is your problem just trying to help. I would take 86TpiTransAms advice with replacing battery and trying to get parts store to exchange alt any way.

 

Ok, I am getting a new battery today and hopefully that will fix the problem. Last night when I got home I sat in my driveway with the brights on and the 4 ways. The battery level dropped to just over 8. Whenever I reved it up just a little bit, the lights would get brighter and the battery gauge would jump to just below 13.

It seems like an alternator not giving enough power, but I replaced mine and had my old one tested and found that it was good, so I doubt that is the problem. Hopefully replacing the battery will fix it, but is there anything else this could be? Thanks

 

Typically when the voltage increases due to revving the engine, it's the alternator. However, like I said before the battery can be causing this issue so replace it and see what happens.

If that doesn't work, look seriously again at the alternator and the wiring. I would replace the wire coming off the back of the alternator with a 4 or 6 gauge wire. You might also consider replacing the alternator with a higher amp unit if nothing else helps. You can switch to a CS-144 (140amps) unit off a 90s model Caprice or Caddy with little, but some, modifications. I think the '87 had the CS-130 unit and if it does, you should be able to get a 140amp CS-130 Powermaster unit through Jegs or Summit. Even if your '87 still has the SI unit, you may still be able to get a higher amp direct bolt-in SI unit from Powermaster. You can go to www.powermastermotorsports.com and email Powermaster directly to see if they have a unit for your car.

Hopefully the battery will fix your problem though.

 

I got a new battery and put it in. It didn't really make much of a difference, so I had a look at some more cables. I found that someone soldered the wire from the alternator, electric fans, and fuel pump onto the auxiliary cable on the positive battery cable. I redid that by hooking up the fuel pump directly to the auxiliary cable and then using o-ring connectors too hook up the fans and alternator to the positive battery connector.

It helped out a lot, but for some reason my gauge still reads a little bit over the line just above 8 after I drive for a while with my lights on and then sit in my driveway with brights and 4-ways on, but it never goes any lower than that even when I leave everything on for a few minutes. Is this normal? Thanks