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View Full Version : Alternator B+ Terminal continually corroded


Atmisphere
10-28-2002, 10:02 PM
I got a relatively new alternator about a month and a half ago. It worked fine for a while, then one day I was driving and the power in my car started flickering. I got out to check the problem and I noticed that the B+ terminal on the alternator was taking on a rusted color (brown and white). The car continued to work fine again after I checked, then the flickering happened again, then the car just didn't start. So, I went to take the alternator back and got a new one. This one had the same problem, without the flickering though, it just got very corroded. And twice my car wouldn't start, with this alternator.

I think that it's possible that water is getting on the terminal or something because the terminal cap broke off when I installed the 1st new alternator. I've never had this problem before either. Now, the alternator isn't totally unusable. Once the car starts up, the alternator still provides power to the rest of the car, but its not (or barely) charging the battery.

Why is the B+ terminal corroding?

alanseijas
10-30-2002, 06:28 PM
The nickel cad plating is worn off of your stud. That's the stuff that gives it the bright shine, and prevents corrosion. Take the wire off, clean them (the stud and the wire ring) well with sandpaper, put the wire back on and use "QuickCoat". This is the stuff that the auto electric shops put on battery terminals to keep them from corroding. You could also use grease, or even this stuff called "Liquid Tape". Coat it well, and it won't happen again.

Apocalypse
10-31-2002, 01:47 PM
Word :scholar:

Atmisphere
11-02-2002, 03:30 PM
All that is good to know, but what is causing the corrosion in the first place: water, shortage, i don't know?

alanseijas
11-02-2002, 04:52 PM
As I said, it is probably the absence of the nickel cad. plating on the stud. Just coat it, and forget it!

Atmisphere
11-02-2002, 05:51 PM
Yeah, i think you're right. I did a number of voltage tests today. I took off the bolt securing the connector to the pole, and test the connector itself while it was on the pole. The voltage came out to 11.9. It was 11.9 all throughout the system when the car was on. But when I tested the B+ pole itself, i got 15.4v. I'm either going to sand down the connector or just replace it, and put the cover over it. Thanks for your help. I was a bit skeptical cause it sounded a little too easy.

turbofwdtsi
12-15-2002, 11:16 AM
Which terminal is the B+ Terminal? I have 3 wires connected to my alternator. The harness w/ the 2 wires, then the black ground that goes near the pivot bolt. Where is the B+ connector at? I'm lost & I"m only reading 11.9 volts myself. Please help!!!

Rob

alanseijas
12-15-2002, 11:32 AM
You can test your voltage right at the battery.

Are you reading it at idle? If so, you've got a bad alt. Must show at least 13.2 volts.