Why is voltage so high

[Ncbimma]

1. New battery

2. New alternator 

3.car runs and drives fine.

 

I was wiring up my external gauges and found my volts were pretty high.

 

Car position 1 ignition:

 

Car fired up and idling:

 

Car off at starter power source:

 

Seems like my voltage regulator is on the fritz or would the alternator be the issue?

 

Thoughts?

[OriginalOwner]

Voltage regulator problem(s), allowing overcharging.

 

Here's my recent adventure on the topic .....

    

 

Cheers,

 

Carl

 

Edited February 9, 2018 by OriginalOwner

[Ncbimma]

No water on my battery...yet.

 

I just got new ground straps and wires. I'm going to swap out all and see what happens.

 

Next I'll explore the regulator

[abe2002tii]

I put my money on the regulator.  Alternator is obviously charging and it is controlled by your external regulator.  It is also cheap and easy to replace....so go there first.

IMHO

Abe

[Dudeland]

1. New battery

2. New alternator 

3.car runs and drives fine.
 
I was wiring up my external gauges and found my volts were pretty high.
 
Car position 1 ignition:

 
Car fired up and idling:

 
Car off at starter power source:

 
Seems like my voltage regulator is on the fritz or would the alternator be the issue?
 
Thoughts?

Voltage regulator for sure

[Ncbimma]

So after a good wire brush scrubbing of ground points and new wires and strap I get the following at idle: (taking at the switched source of my console gauges)

 

But rises aggressively at 2k rpm and above:

 

Should I be concerned?

[jmiller]

Need new battery for the VOM?

[Ncbimma]

48 minutes ago, jmiller said:

Need new battery for the VOM?

The vom and volt gauge are mostly the same measurements.

[thehackmechanic]

This is a stock alternator that uses the external regulator? Unplug the plug that goes into the regulator and then check the voltage. You should see "battery voltage" with the car running -- about 12.6V. Then plug it back in. You should see "charging voltage" -- about 13.5 to 14.2V. 16V is much too high, and indicates a bad voltage regulator.

 

If you have a new-style alternator with an an internal voltage regulator (integrated with the brush pack), you still should see the levels I said above, but there's no real way to test it without the regulator, since it's part of the brush pack.

 

Either way... almost certainly the regulator.

 

--Rob

 

[TobyB]

Regulator...

....or something messed up in the wiring to said regulator.

 

t

 

[Ncbimma]

I will check out the regulator in the AM. It has an external one on it.

 

But doesn't the Tii also have another regulator and is there a need for both of them or can I omit one? I bought a new one (yellow tape) maybe 6 mos ago.

 

Forgive me because I'm electrically stupid. I surprised myself by getting the volt gauge and temp gauge working (not illuminated yet).

[ray_]

39 minutes ago, Ncbimma said:

I will check out the regulator in the AM. It has an external one on it.

 

But doesn't the Tii also have another regulator and is there a need for both of them or can I omit one? I bought a new one (yellow tape) maybe 6 mos ago.

 

Forgive me because I'm electrically stupid. I surprised myself by getting the volt gauge and temp gauge working (not illuminated yet).

'tis but one regularor

 

 

[AustrianVespaGuy]

Also make sure that the body of your alternator is grounded to the engine block/chassis! I think this would normally result in no charge coming from the alternator, but easy thing to double check before replacing parts!

[Ncbimma]

2 hours ago, AustrianVespaGuy said:

Also make sure that the body of your alternator is grounded to the engine block/chassis! I think this would normally result in no charge coming from the alternator, but easy thing to double check before replacing parts!

Yes. That's what I just replaced today. 

 

1) The alternator had the original old dingy ground wire still and it went to the block. I replaced this with a new 10 Gauge wire/ crimp terminals

2) There was a ground strap at that same block bolt where the alternator ground wire ended and the strap went to the chassis.

3) I removed all of those and brushed the surfaces with a wire brush to get all (most of) the gunk off

 

4) What I mentioned prior was ... does the AL40X alternator actually have a regulator on the back too? (that little black box on the back) Or am I just a moron? Or both?

 

 

5) I just replaced the BMW voltage regulator less than 100 miles ago. Do I test this part by unplugging it with the car running and then checking volt?:I still have the old one too, might be worth while swapping back to test out as the old one was just replaced for the hell of it during some csv issues...

 

 

Thanks everyone!

[Simeon]

If the AL40X has the three pin plug on the back then it is an external regulator alternator. Try your old one in place.