racerseks

In regards to a '96 CE, with LT4...

Just put in a rebuilt alternator, and I get crazy sparks when hooking up the negative cable. I replaced the alternator, the alternator connector, the battery, and battery terminal bolts. I should add, that I used butt connectors on the connector. I prefer to solder them in, but one wire was real thick, and just couldn't get a satisfying connection with solder...so I went with butt connectors, and shrink wrapped 'em. The battery was bought a few months ago, but not used. Kept it charged on float charger, but had it checked out at the place I bought it at earlier today. It's rated 690CCA, but measured 792 CCA.

Any tips on where to start the troubleshooting?

Thanks!

Whaleman

I am not an expert but if you are getting sparks when connecting the neg cable you MUST have a big draw when hooking up. Dan

JimLentz

Disconnect the positive terminal from the alternator and try again.

Bagpype

Something is grounding. Check your wiring that you touched. I had the exact same problem on a 1991 that I replaced the engine in. Turned out my positive battery cable was grounding at the starter. Hell of an arch when I tried to connect the neg terminal on the battery.

racerseks

Yea, that's for sure...thanks!

racerseks

I've thought about it, but the sparks were so massive, it seared the terminal up pretty good on that side, and I'm kinda scared it'll do the same thing. Thanks!

racerseks

Yea, I hope to do that later tonight, but raining all day and night here. Waiting for a break. I've seen a few mention the starter...never touched it. Could it have been moved simply by tugging on the positive cable? I didn't pull it very hard, but it was hard getting the new terminals in. Yea, same here... would make a decent makeshift welder. Thanks!

racerseks

Oh yea...Is the starter down towards the transmission on the passenger side? Never had to mess with it on one of these...always been pretty bulletproof. Thanks!

racerseks

Any thoughts on whether I might just have got a dud? Wondering if I should take the alternator out and have it checked, before the store closes. I'm not the fastest guy at this stuff, and might run short on time. Thanks!

racerseks

Sorry, I just read this over again. So you mean try starting it with the "hot wire" on back of the alternator disconnected? If there are no sparks, what does that tell me? Bad alternator? Thanks!

JimLentz

I thought the spark was from just connecting the battery. If you connect it like before and no spark the problem is with the alternator.

racerseks

Yes, it's when I hook up the battery. But the problem just started after I replaced the alternator.

JimLentz

That is why I suggest you disconnect the positive terminal from the alternator and try it again. If the alternator is shorted out internally when you connect the battery after disconnecting the alternator the sparks will stop.

SJW

You have a dead short to ground. Check to make sure the hot lead at the alternator isn't touching the alternator case, or anything else other than the post it's attached to. If everything looks okay there, take that alternator back and trade it in.

Live well,

SJW

racerseks

I gotcha! I read your reply a little too quickly the first time, but I think I follow now. Thanks!

racerseks

First thing I had planned to check. Woulda done it last night, but I just find, if something goes wrong, shut the hood, and give it a fresh eye the next day. In my S10, everything is easy...but these things are finicky!

I'm usually doing this stuff late at night under a flashlight, and when I runj into a snag, most forum members all long asleep...So please keep the tips coming! I'll have more things to try when I am out there at 3:30am,

Thanks!

PatternDayTrader

Very likely.
​​​​​​​Do what Jim said and find out.

Hot Rod Roy

Here's my trick when I think there might be too much current flow, due to a short circuit or a bad component somewhere. Solder (or clip) two wires to an old (but good) headlight. Connect the headlight to the two wires in question. If the headlight shines bright, you've got a short, but nothing will spark or smoke! The may be a small glow to the headlight to indicate a good circuit.



Don't try putting an amp meter into the circuit.

racerseks

Going back over the newest replies, but trying to beat the rain...and not much time left.

My replacement connector looks a little messed up, so could be it. Can anyone tell me what the three wires in this four pin connector are for? It might help to understand what's going on. Can't tell if any are touching each other etc., but they are a bit out of shape. Thought I might try this angle before the suggestion of disconnecting that lead, and trying again...Forgive me, but it sparked so much, it took a chunk out of my terminal immediately upon contact, and I am kinda scared I might mess something else up.

Thanks!

PatternDayTrader

Holy crap pal .... Take a picture of the heavy gauge red wire where it connects to the alternator and post it so we can see.. The terminal that protrudes from the alternator case is insulated by a red plastic "insulator" and if its damaged, perhaps because you overtightened it, or perhaps because its a piece of ****, then it will do exactly what you are saying ....