Paul L

If yes, I am looking for the gauge of the wire that hooks up to (+) on the dash voltmeter. I assume ground (-) would be the same.

OMF

Check this out...
http://corvettec3.com/cgi-bin/yabb2/...num=1270703107

BigBlock77

If I'm reading the diagram right, power is fed to the printed circuit from the 10A gauge fuse with a pink 18ga wire. The ground for the volt meter off the printed circuit is a 14ga black wire.

Paul L

I asked the question the wrong way. Apologies. If I installed a voltmeter instead of the existing ammeter in my 1974 what gauge wire would I use for a switched (+) feed? I'm thinking 16-gauge. The ammeter wires would be secured away behind the dash with appropriate insulation so as not to cause any shorts.

lionelhutz

The voltmeter is a low current draw so the wire size feeding it really doesn't matter. So, size the wire so the fuse protecting the circuit you're connect to will protect the wire. I'm thinking 16 gauge would work connected to most of the switched circuits in the car where if it did short the fuse would protect it.

Paul L

Thank you. I will go with 16-gauge wiring. I will probably hook into switched IGN at the fuse box and that should be OK.

Peterbuilt

Yes! That will work and you can attach the ground to the BLACK wire on the temp gauge.

Paul L

Thanks. I may just go to a ground on the frame. Why temp gauge?

Peterbuilt

[QUOTE=paul 74;1590109367]Thanks. I may just go to a ground on the frame. Why temp gauge?

Because that is the ground for all the gauges and it will take a short wire, but any good ground will be okay.

Paul L

[QUOTE=Peterbuilt;1590110965]I did not know that. Thanks!

Rotonda

The 77's gauges are all fed from the 10 amp GAUGES FUSE into an 18 gauge pink wire through the printed circuit. Current exits to ground from the printed circuit through a 14 and an 18 gauge wire.

18 gauge to and from your voltmeter will be plenty.

Paul L

The 1974 does not have a printed circuit...so I will have to wire the voltmeter separately to switched 12V and a dash ground. I am still leaning to 16-gauge.

0Willcox Corvette

Paul... Snag a copy of this too. it's what we call a tracer schematic. Copy the picture and paste it in your "Paint" program. Then save it as a BMP (you won't loose quality). When you open it in paint you can trace wires real easy.

http://repairs.willcoxcorvette.com/1...cer-schematic/

Paul L

Thanks for that!

0Willcox Corvette

Least I can do Paul and your most welcome.

We use these trace schematics almost every day. Once we trace out a circuit we save them to the main server so we don't have to do it again. But it's a nice way to isolate a circuit for sure.

I've been trying to get all of them up on the site but my time has been limited the last few months.

Willcox

Paul L

I won't explain how I ended up with two 1977 voltmeters. But I have two, one is NOS. But to cut to the chase (again maybe I am thick) where do I get a 12V switched source? The 1974 does not have a printed circuit. I use ACCESS for DRLs and the IGN seems occupied as well. Do I tap into one of those? Sorry to be such an electrical neophyte, but I am.

0Willcox Corvette

I'd either go to the fuse panel or the ignition switch connector at the steering column. I'd prefer the fuse panel though.

So.. your trying to install this in your 74 right? Do you have power windows?

If so the plug for the power windows has a jumper built into it so you could saddle up on that terminal. If you don't have power windows you could use this same lug in the fuse panel for your power source.

I'll take a look at this tomorrow when I get a chance. I need the 74 schematic too. (not on the site just yet).

In the fuse panel below, you have Bat, Acc and Ign... See if you don't have one of those in your fuse block. That's what I would use.



Ernie

Paul L

Thanks Ernie,

I will check tomorrow. Too tired this evening to crawl under the dash. Age has consequences!

0Willcox Corvette

Paul... are you installing that gauge in your car? If so, below is how you would wire it....

The switched voltage you can pick up from the ign or the Accy lug in your fuse panel. Both are switched. If you have power windows you'll have a jumper like the one pictured below and you can jumper in on that one too. You have some options for sure.l

Paul L

Yes, the objective is to replace the ammeter in my 1974 with the voltmeter.

I currently have my daytime running lights (DRLs) hooked into the ACC lug. I do have power windows and that is hooked into the IGN lug with the wire and jumper as you have shown. The jumper is unoccupied so it looks like that is the target for the 12V voltmeter power source although I do wonder if the amperage in that heavy gauge wire might be too much for the meter. My thanks to you for your informative reply!