Jump to content
Ultimate Subaru Message Board

Low interior voltage meter reading


Recommended Posts

I'm confused by my interior volt meter reading. It shows 10V. Where is the interior volt meter measuring that voltage?

When I use my own volt meter I don't get any reading near 10V, but I don't see any reading around 14V like I expect to see.

* I read 12.6V across the battery terminals.

* I read ~12.6V from the eye terminal to ground on the engine case

* I read 18V (a lot!!) from the alternator positive output post to ground on the engine case

* And, hey, why do I get a different reading between literally the post or the eye terminal? They're touching the same thing!!

I thought I was dealing with a bad wire somewhere but I've replaced a noticeably bad wire and I can't find what looks like any voltage drops between the alternator and the battery.

The eye terminal and the wire on the positive alternator post have gotten physically hot to the point where they melt plastic on the wire. 

Check out pictures to see the melted wire.

My best guess is there's still a bad wire somewhere. Or maybe the alternator is bad? Shouldn't it read 14 or 16 volts and not 18 volts? Any insight is appreciated!

And again, my original question is where exactly is that interior volt meter measuring that voltage? I really don't understand why it alone shows 10V.

Screen Shot 2022-05-30 at 10.31.30 PM.png

Link to comment
Share on other sites

Maybe my eye terminal just isn't actually contacting the positive output post? I really don't understand how I get two different readings from touching the post or the eye terminal.

 

Here's a photo of the not-burnt connection.

Screen Shot 2022-05-30 at 11.00.00 PM copy.jpg

Link to comment
Share on other sites

Note it is also possible that the second nut, that holds the stud in when the ring terminal is removed is loose. If it is loose,  the connection on the inside could also be causing heat and corrosion,  so it should be checked also. 

Link to comment
Share on other sites

  • 3 months later...

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.

 Share

×
×
  • Create New...