Voltmeter reading? Accuracy? Options

[SKL1]

Looks like I'll be taking out the alternator with the engine in the car. Not impossible but having been around these engines for 55+ years, both in and out of the car, it won't be fun.
Any quick suggestions? Can it been done leaving the front cross sheet metal piece in place?
Luckily it is on a lift right now...

[GregAmy]

It's an up-down-up-down game. If you have two people it goes quicker.

I have successfully removed the front transverse sheet metal to work on the nose of the engine; it's fiddly but do-able. Next time I have to replace an alternator that's what I'm doing.

EDIT: as for re-wiring, I tested the voltmeter at the battery and it was reasonably accurate, its issue is that it's connected to a shitty circuit, at the power side of the brake light switch (yup). It's grounded on the same circuit as the other gauges and dash lights.

I would not be surprised that if you moved its power wire (red/white) to another circuit under the dash then it would be fine. Fuses S11 and S13 go straight to the battery.

[Spoke]

Looks like I'll be taking out the alternator with the engine in the car. Not impossible but having been around these engines for 55+ years, both in and out of the car, it won't be fun.
Any quick suggestions? Can it been done leaving the front cross sheet metal piece in place?
Luckily it is on a lift right now...

@SKL1

Good luck with the alternator R&R. I looked through this thread and didn't see if you confirmed the GEN light on with key in and engine off then goes off with the engine running.

BTW, I tested my voltmeter with a digital VOM and found the voltmeter itself is very accurate to about 0.1V. As mentioned it's the placement of the voltmeter in the vehicle wire harness which generates the error from the battery. I find with my voltmeter in the stock location the voltage shown is about 1V lower than battery voltage.

[porschetub]

One of these days I need to run a wire back to the battery for the volt meter.
My car had a long history of electrical gremlins, which I have resolved over the years. But the volt meter is a cause for stress as it currently gets hit by load when the lights and wipers are working, and does not give an accurate view of what's actually happening at the battery.

Zach

I have a Hella 5 fuse unit and to also wire in supply for other items, plan is to reduce load on the OG fuseboard which is somewhat limited anyway , my wiring is in great condition and prefer not to overload it .
See a question about where to run this wire, I ran mine down to top of the tunnel but don't remember exactly but pretty sure I came thru the bulkhead and fitted a grommet and shielding over the wire up to the battery .
Cheers.

[SKL1]

Spoke- I will check the Gen light tomorrow to see how it operates. (BTW I love your LED bulb conversions)

[JamesM]

It means either the alternator is shot or your voltage regulator is shot. The vr is 35 dollars so start there. If that doesn't fix it then the alternator. Not terrible to replace or pay for. That difference between the battery and the gauge is what you get unless you alter the voltmeter wiring.

or your wiring harness is shot
or your relay board is shot
or your alternator light is shot (and or wrong)

[emerygt350]

It means either the alternator is shot or your voltage regulator is shot. The vr is 35 dollars so start there. If that doesn't fix it then the alternator. Not terrible to replace or pay for. That difference between the battery and the gauge is what you get unless you alter the voltmeter wiring.

or your wiring harness is shot
or your relay board is shot
or your alternator light is shot (and or wrong)

true, maybe replace your wiring harness relay board first (IMG:style_emoticons/default/wink.gif)

[VaccaRabite]

Do Spoke's tests before you replace anything.

These tests will determine if 1) the alternator is charging, 2) the regulator works.

Once those are confirmed, we can test for voltage drops due to poor grounds.

Zach