Alternator glowing..??

[st2b]

Well, we polished the Intake manifold and got everything back on, but before we removed it all, we noticed the guard over the top of the alternator terminal was burned...

So we just decided to wait till today and see if I can find something through search. After polishing all night and searching the forums for a little while, I couldn't come up with anything. It's not blowing my Alternator fuse, and nothing looks out of the ordinary.

I mean, mechanical problems is my thing, but anything to do with wiring, is NOT my thing.

We didn't move any type of wires (Other than unpluging plugs, so I know we couldn't have messed with anything.

Symptoms

1 Upon clicking the key to "IGN" (But not start) I hear a clicking noise coming from the engine bay (Passenger side near the firewall)

2. When I turn the key to start and the engine cranks over and starts, the alternator shoots sparks (Just for a second until started) from that terminal.

All my fuses seem to be fine. The terminal on the battery is fine, and the alternator. I even unplugged the wiring harness to the stereo because that's the only wires I remember messing with and it still happens.

If anyone could help me out that would be amazing

-Matt

 

[jetjock]

It's not supposed to do that

Start by making sure it's clean and tight ie; disconnect the battery, remove the nut on the terminal, clean it and the stud up, and reinstall. Don't overtorque it. Before you do that you might want to measure the voltage between battery positive and first the ALT terminal and then the stud. Set the meter to DC millivots and do it with the engine running. Do the same between the battery negative and ALT case. Anything over 100 mv is bad.

 

[st2b]

Meaning a bad battery?
Or a bad alternator?

Both the battery, alternator, and starter are new, but this problem is recent.

 

[jetjock]

Could be a few things but it sounds like a bad connection at the ALT terminal. Because of how it's constructed the stud could even be loose inside the ALT. That it's all been messed with recently is suspicious. Measuring it will instantly tell you whether there's a problem there or not. Or you could flounder around throwing parts at it like many here do until it's fixed...

 

[st2b]

But I don't have anything that will measure any type of current (Besides a double A battery).

I thank you for the information and I might be able to borrow grandpas meter later on today.

Thanks!
Matt

 

[jetjock]

Measure current with an AA battery? Uh, just start throwing parts at it

Seriously, if you're going to work on cars you need to buy a decent meter and learn how to use it. It'll pay huge dividends when working on lots of things besides cars and spare you a lifetime of electrical frustration.

 

[st2b]

Yeah I was kidding about the AA thing, and I'm working on getting one, but I'm 15 and don't have the money for one :/

I know they aren't expensive, but I'm broke, like 0.00$

 

[jetjock]

Well, a good one is actually fairly expensive but you can start out cheap. For now check that everything is tight and clean.

And if you're broke this is not a good car to own. Since I know you're 15 here's a tip to avoid staying poor: Pouring money into a depreciating asset is financial lunacy

 

[BlackDynamite]

See my dad is an electrician so i have meters GALORE!.....But i had a very similar problem....When i first rebuilt the car, i put the alt that came with it back on. Well it got really super hot and melted the cap on the connection on top of the alt. I replaced it and the battery. The battery i had was dead and i think it made the alt work overtime. But it runs fine now, just when putting it in gear, turning lights on, flood lights, turn signals, etc. The lights dim, and the volts gauge drops for a second....

 

[cuel]

St2b: Don't overtighten the nut on the alt. terminal. I see this a lot. It'll usually twist the whole stud, which breaks the connections inside the alt. Makes it a big PITA to get back off as well. Do as JJ suggested, and check all the connections.

 

[jetjock]

^ Right, many people do that, which is why I said not to over torque it. In fact he may have already done so (assuming he did the work) and damaged the internal connection to the diode pack. I'm hoping it's just loose on the outside though.

Off topic a bit but I recently overhauled my original ALT for the second time. Cleaned, dressed the slips rings, and replaced the brushes and bearings. Got a good deal on the bearings from Amazon.com of all places. Genuine Koyo too.

 

[cuel]

Hmmm... I need to do that for my 87 Prelude S. Never have tried rebuilding one myself. Done a few Polaris starters, though.