austinseanchris

Hey guys, maybe someone with some knowledge of the C4's can shed some light on this issue that fell in my lap tonight. I took the 96 out tonight and had been driving it about 45 minutes. Everything was fine and I thought I noticed my interior lights dimming and then going back up to normal setting. At first, I thought my eyes were playing tricks on me until I began watching it harder. Then all of the sudden, my "Airbag" light pops up on the information center display. This continues for about 2 minutes. Then all of the sudden, the light goes out and everything returns to normal. The car was running fine through this whole process. I hit my gauge button over to Volt and it was reading 14.5 volts. I drove about another 10 miles and it started bouncing back and forth between 14.5 and 14.7. Then about 3 minutes later, it jumped up to 15.0, then 14.5, then 16.0, then 14.0, etc. It began bouncing all over the place and my interior lights started dimming down and going up again. It finally peaked up to 17.0 volts and a red "Check Gauges" light turned on so I pulled over immediately. I got out and checked everything under the hood as far as connections to the alternator and I didnt see anything else that looked out of the ordinary. After sitting about 5 minutes, I cranked it up and left. I was about 2 miles from my home and when I had went a mile, it jumped to 16.7 volts and stayed there until I got home.

Now, I know on my 78, a similiar situation occured with a huge peak and you could literally hear the alternator sound like it was in supersonic mode. I wound up shorting that alternator out and frying it. So, is this whats happening here? Is this a sign the alternator is going out or some other electrical problem? And for what its worth, I didnt have the radio on or anything like that...I hope this is something simple and not too costly...Any help would be great...

Lemme

Sounds like a voltage regulator problem. As the voltage regulator is internal to the alternator then you probably need a new alternator.

austinseanchris

Well, after reading your reply and other posts on similar issues, I think your right with that verdict. How hard is removal and installation of a new one? Any tips/tricks or advice I should know? And lastly, do you know anyone who makes a black alternator? Thanks!

pcolt94

Unless you want to rebuild the alternator and replace the voltage regulator. Or get a alternator with a life time guarantee.

Although it sounds like the alternator, on occasion I have seen a battery cause the voltage the jump around also. I have see it and have it happen to me but not in the vette. I might just get the battery checked just to see if anything shows up to be on the safe side.

How old is the battery and is it subject to a lot of heat where you live. In Florida I am happy to get to 3 years.

austinseanchris

The battery is 2 years old this August. Heat, lol, we're having the hottest summer in history here in NC...101 degrees yesterday! Ughhhh! Well, if I'm gonna have to rebuild, I'd probably be better off just buying a new one since its probably never been replaced.

96_LT4_FE1

Rebuilding alternators is pretty easy, but if you decide to buy a rebuild, get a good quality one. I've replaced, or helped replace, quite a few "rebuilt" alternators for other people.

Probably the toughest thing about rebuilding an alternator now is finding the kits, they used to be easy to find, but the last time I looked, I couldn't find the one I needed. Also, if you do decide to rebuild your own, mark on the case how it is "clocked" before taking it apart. Some alternators can be assembled up to 4 different ways depending on the vehicle they are put in.

I agree with testing the battery too, since you are there anyway.

Autozone and other places will often test alternators and batteries for free. Of course, make sure it is a place you can trust.

Either way DO NOT drive it like that if you can help it. Auto electronics are tough as hell, but they can only take so much before they suffer permanent damage.

jfb

Your alternator has a defective voltage regulator and if you want to, you can replace it yourself. If you don't want to bother, then get a new or requilt alternator. Not much over 17 v and you will fry your onboard computer which is a lot more expensive than an alternator.

austinseanchris

Thanks guys for all the help. I was concerned with me driving it and how it would effect it. Hope I didnt mess anything up by driving it that last couple miles??? I know on my 78, I could have continued to drive it b/c there are no computers in it...it just would never charge the battery. Nonetheless, I just purchased a Powermaster 200A Black powder coated alternator. With my engine dressed the way it is, I wanted something that would match a little better anyways. Everyone knows that cast is ugly as can be! I didnt think Chrome would look that great with my setup so I went with black. Of course, it was more expensive than any of them. $439.00! But, sometimes you gotta pay for the things you want, right? I figured with the 200A, I plan to be putting a stereo w/ 2 amps in by the end of the year and figured that'd help push it a little better.

One last question, how hard are these things to put in? Is it pretty simple like on the older cars or is this something I'm gonna wanna shoot myself after I get done? Would this be a good time to go ahead and replace the belt as well?

Thanks again!

coupeguy2001

It is just as simple as older cars except for the serpentine belt. Which is easier than tightening 4 belts.
disconnect battery to be safe.
Just for your own edification, clean your battery cables first, then recheck for the problem

jfb

It is easy to change the alternator. Remove the negative battery cable first. Use your 1/2" breaker bar on the belt tensioner to remove the tension on the belt and move the belt off the alternator. Unplug the alternator and unbolt its output terminal wire. Remove the top and bottom bolts that hold the alternator and remove the bolt on the back brace and remove the alternator. Reverse the procedure to install the new alternator.

austinseanchris

Thanks and sounds easy enough. Should I go ahead and replace the belt or am I asking for problems doing this?