No charge issue 2001 vette

[c5havin]

Hello Gang. I have a 2001 Corvette coupe. A couple weeks ago, I started having charging issues. I noticed it when it would randomly trip a service traction control code. I traced it down to loose battery cables. Things were fine for a week. Last week I was getting a "no charge" condition, with pcm codes 1637, and pcm 1638. While I was on my way home after noticing that, It started to charge normally at 14 v on the guage. Today, "no charge" issue is back with the same two pcm codes. I know intermittent problems are a pain to diagnose, but can you give me a place to start? Thanks in advance

[c4c5specialist]

HI there,

I would be wondering if there isnt a connection issue at the plug going into the alternator.

Both these codes can set in 2 ways, either with the key on, engine off or with the engine running, so I would be more curious WHEN the code goes current.

Disconnect the plug at the back of the alternator and take a good look at the terminals to make sure they arent spread apart giving intermittant contact.

If not, then I would be tracing the wiring back to the PCM to determine if anything has rubbed through.

Remember, if these wires going to the back of the alternator are shorted to ground, THEY WILL NOT blow a fuse.

Allthebest, c4c5

[c5havin]

Thank You for your reply Paul. I started looking around last night, after I had found a charging system flow chart. In the key on/engine off position, I am getting no juice to the back of the alternator, and no juice at the "s" terminal with the top plug unplugged on it either. Same issue with the car running. The Junkman sent me a schematic last night. If I'm reading it properly, there are 2 fusible links coming off of the starter going to the alt. Is that correct? Thanks in advance

[c5havin]

In answer to your question Paul, The "no charge" message only when the car is running, not when the key on/engine off. I hope this helps. Thank You again.

[c5havin]

After some searching around today, I found that the starter solenoid was "baked" at the large positive side. The wires were tight to the post, but the post was loose in the solenoid. I cked continuity thru the wire that comes from that post and goes to the back of the alt, and continuity is there. Could the solenoid be the issue? I'm replacing the starter with the twin long bolt style as I have read horror stories about blocks breaking in that area. Thanks in advance, Mark

[c4c5specialist]

HI there,

That means that someone is OVERTORQUING the bolts and breaking them.

They NEVER EVER break under normal usage.

Allthebest, c4c5

[c5havin]

Originally Posted by c4c5specialist

HI there,

That means that someone is OVERTORQUING the bolts and breaking them.

They NEVER EVER break under normal usage.

Allthebest, c4c5

I bought the car used 4 years ago. The starter doesn't look like it had been down yet, but there was visible cracks, and a spot where the solenoid had gotten hot, and distorted the end cap at the connections. Since I didn't have juice to the alt yesterday, and I do have continuity thru the wire, could this be my problem? Thank You

[c5havin]

Well it seems that the solenoid was the problem. Fired her up, and she is charging as she should. Now just to climb back under her and throw a shim in the starter. It's a re-manufactured AC/Delco unit. Hard to believe I have to shim it.

[c4c5specialist]

Yea, I would be a bit worried about that as well.

Shimming starters in this day of technology is not usually recommended.

Allthebest, c4c5

[c5havin]

I ended up taking all the shims out. It seems backwards, but the more shims that I put in it, the louder the starter became. Thanks for all of your input bro. Have a great day!