Jump to content
HybridZ

Overcharing? 16v at any RPM...


Recommended Posts

I did some searching and found that it wasnt good obviously and that it can have some bad affects on the battery. Ill have to wait till I get all my lights in to test for brightness or if they get blown out. Is there anything I can check that might show where the culprit is?

 

Thanks, btw car is a stock 78 l28.

Link to comment
Share on other sites

Check the battery sense wire coming from the alternator to a battery hot source, typically found off the wire from the starter solenoid back to the harness. I can't say for 280zs, but for 240zs this wire had a fusible link which could pop.

 

Check this line/fusible link. If the alternator does not "sense" voltage from the battery, it will overcharge.

Link to comment
Share on other sites

Are these voltage readings from off the stock gauge?

 

If so then you probably don't have a problem. My 77 has always read at around 16v with the motor is running, and this is with multiple alternators and even two different (stock) gauges. Mine also reads at about 12.5-13 or so volts when the car is off.

 

I vaguely remember reading about this a couple years ago, and that its a non-issue.

Link to comment
Share on other sites

I also ran the same cheap O-Rielly battery for over 5 years. So I highly doubt there is an overcharging issue. If you want to verify that you're fine, just use a multi meter across the battery posts when the motor is both off and running. when off voltage should be between 12-13 v and running/charging should be around 14.4v

Link to comment
Share on other sites

Are these voltage readings from off the stock gauge?

 

If so then you probably don't have a problem. My 77 has always read at around 16v with the motor is running, and this is with multiple alternators and even two different (stock) gauges. Mine also reads at about 12.5-13 or so volts when the car is off.

 

I vaguely remember reading about this a couple years ago, and that its a non-issue.

 

Ok well then i'm probably ok cause thats exactly what mine does.

Link to comment
Share on other sites

Thats what I read so Ill try that. I was just outside and with the key out it is at a little past 12v. Is that normal?

 

Im actually kind of happy having a mechanical issue for a change! :)

12.5 to 14.5 is normal. When your car is off and your battery is fully charged it should read between 12.5 to 13 volts. Double check your voltage at the battery, if it still seems high, check your fusable links and if that's not it you might need to adjust or replace your voltage regulator.

Link to comment
Share on other sites

Yea, mine can read anywhere from 13 to WAY above 16 on the stock guage.

 

Been running just fine for 6 months + now. It's a guage issue, not a voltage regulator issue. At least for me it is. You should still check the battery with a multimeter when it's running though. Just to make sure.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...