racerseks

This is for a 1996 Corvette Collector's Edition Coupe, with LT4/6-speed.

I'm looking through the forum trying to find info on this, but thought I might post a new one and see if I get something more specific.

The car starts up and runs. Battery light came on and stayed on. I think the volts were around 10, so kinda surprised that it started right up the way it did. After taking it for a ride, volts dropped all the way down to 8, and it died in the middle of the street. Got a friend to try a jump. Busy street in a not-so-great part of town, so we didn't let it charge very long. It cranked...a bit on the weak side, but my buddy had to get up early the next day...so we went and bought a battery. It started right up again, but battery light was still on. On the way home, the headlights were very dim.

Will a code scanner tell me anything? Where is the port located on a '96? Is it the same spot as the earlier cars? Thinking alternator, any thoughts, test procedures, etc.?

Thanks!

PatternDayTrader

So just reading your post makes me 99% sure you should replace the alternator.

billschroeder5842

Yeah, your alternator is toast. Swap it and you will be good.

racerseks

Thanks...would the battery symbol pop up for the alternator? Would a code scanner confirm. Is the port above my right knee when sitting in the car?

Thank you!

racerseks

Thanks...would the battery symbol pop up for the alternator? Would a code scanner confirm. Is the port above my right knee when sitting in the car?

Thank you!

PatternDayTrader

Yes the battery light will come on when system voltage is below a certain number with the engine running. I cant remember if there's a code for it or not but you don't even need to bother with all that. In the event your really interested in this then buy a voltmeter and connect it to the battery, then start the car, if its reading the same or slightly less with the engine running then replace the alternator.

racerseks

Thanks for confirming. Yes, I have a voltmeter, and was planning to check.

Thank you!

PatternDayTrader

Right on.
Let us know how things turn out.

racerseks

Will do!
Hoping to get out there tonight, but been raining...

WVZR-1

You should be able to monitor voltage using the cluster. If you've the FSM see 8D-7 and you can monitor ignition voltage and switched voltage using the DIC.

It should be much easier for you to read it than for me to explain. If you don't have the FSM I could post the page I believe.

racerseks

Sure, if you could post it, that would help...thank you

racerseks

Well, I figured I would start by cleaning the terminals before putting a battery in there and trying it, and they are in pretty bad shape! Cleaned them up real good, took the tray out, etc. Took about two hours. They were that bad...but I want to do it right. Good chance that might take care of it. My S-10 refused to start one time. Thought for sure it was the little switch on the clutch, but cleaned the terminals up real good, and it started right up!

So I'm gonna clean that tray up, and all the bolts before I put it back in. In the meantime, I noticed a bolt that holds the alternator on doesn't seem to be flush. It even rubs against the belt, so that's another possible culprit.

Might not finish tonight, but will continue tomorrow. Glad I didn't buy an alternator just yet, but we'll see...

racerseks

Well, I kept at it. Cleaned up the area behind the battery and tray while that stuff is out. The bolt I was talking about that hits the belt, holds the alternator and ac compressor together. Nothing to hold it in from the back, so it just slides forward and contacts the belt. Guessing there's a nut or a specialty fastener of some kind missing on back. I hunted around here to find a nut that fit for the meantime. Looks like one off a piece of furniture, LoL...so it's not staying! Plus, there's still space in there for it to move. At least I'll know the size anyway, if no one else knows...and can start it up to see if either of those are related to the charging problem.

Anyone have a shot of this area on an LT engine? Guessing it's the same on an LT1 or LT4, but mine is an LT4 if it matters. I'd like to see what's supposed to be there. If it's just a nut, anyone know size, grade, etc.?

Here's two shots...one of me pointing at it, and another with my finger out of the way. Engine needs detailing, but it's warming up here in Florida, so I'll post some when it's clean. Lots of maintenance to do on it before then though...

Thanks!

bac22

That bolt/nut seems to have been replaced at one time, not what should be there:

WVZR-1

An LT1/4 seems to have a GM spec specialty bolt in that application. It's M10x1.5 but not ever owning an LT1/4 I can't comment on the specialty factor. Generally mounting hardware isn't GM specialty. The bushing seems to be in place in the support.

bac22 - What head is on the bolt? Is it Torx maybe? Is that your car?


OP - it is Torx and here's an image I snagged. I believe this is likely correct all LT1/4 from '92 on. Not having a bolt in hand a person can't measure the actual shoulder diameter but it would be hard to believe a specialty diameter. An issue? I'd think not.



CCM information you asked for. CCM data 1.2 instructions begin bottom left column & continue to right column.

racerseks

Does the bolt itself look right to you? Mine isn't torx on the end...just a standard bolt head. Is the nut on the end just a plain nut? How does it fit in that sleeved end without the space? Thanks for posting.

racerseks

Thanks for the info. Head on the bolt is just a standard bolt head, and not torx. Any idea what the nut on the end is like, and is it recessed for that sleeve?

I like original myself, of course...but my concern is more in keeping that bolt head from sliding up into the belt. It was rubbing against it until I put that bolt on the end...and there's a space from that sleeved area, so it may very well do that again.

Thanks for posting that as well...

WVZR-1

So the nut in your snapshot is something you just did?

It's not recessed or anything special.

I'd think you're good if the bolt is actually an M10 - if someone just slipped a 3/8 bolt/nut in there then it would allow wobble but maybe NOT to the point it's critical. The nut on an OE would just be a 'flanged washer' so you could buy that locally easily. A correct length M10 bolt would be likely more difficult. Measure from the front of the bracket to the nut now and you would need a shoulder very close to that length.

racerseks

Missed your question before...Yes, it's my car, and yes...it's a picture I took last night.

The nut doesn't sit flush, and there's space between the nut and the back of the AC Compressor/Alternator. Hoping there's a better way than stacking a bunch of washers. That nut is just something I put on that I found around the house...there was nothing on the end before. Just put it on so I could try it and see if it's the source of my charging troubles.

Thank you!

WVZR-1

I was curious about the head of the bolt. The question 'Is that your car?' was intended for bac22.

The nut you've got there now looks to be a 'ny-lok' and if it actually fits I don't believe it's a problem. It should seat against the spacer. I'd buy a new M10x1.5 nut to try on the bolt to confirm the threads. You should be able to buy an M10x1.5 HFH nut at most any local hardware, the 'ny-lok' feature isn't required. If the M10 doesn't fit properly then I'd think someone used a 3/8-16 bolt. Buy 1 of each to try maybe.

An M10 can be threaded onto a 3/8-16 but I don't believe a 3/8-16 can be threaded onto an M10. does the nut feel loose maybe?

I'd concern myself first with just the charging!!