Volt Gauge

[Tom Vilardi]

Gauge’s on my BCW all come from “Classic Instruments” and are still available.  After going through a bout of battery trouble and the replacement of the fanbelt (instead of the alternator), I got a Volt Gage.

Not having a build manual I was dismayed at the rats next of wires under the dash.  Tried to test a few to find switched hots and grounds and didn’t want to start cutting wires to discover I made a mistake.

I had previously tested the Volt Gauge by using the hot and ground of the battery – with the car off (approx 13 volts) and running (14-15 volts) – worked just fine.  

Put gauge in dash, and figured why not run it just like the way I tested it – ie, right off the battery……. 

So is that a big mistake (will the gauge pull any volts off the battery just for the read and eventually die), or am I okay with this set-up until I can find the time to pull more of the under dash wiring apart.

Tom 

 

Tom Vilardi
BCW Model 52
South Orange NJ

[Court Wizard]

hooking direct to the battery will create a constant drain. you want to connect to the “ignition” side of the ignition switch. that way the gauge will come on with the other instruments and show the voltage in the system.
But when you kill the ignition there won’t be any drain on the battery.

No trees were injured in the making of this message, but some electrons were inconvenienced.

[Toller]

I replaced the amp meter with a VDO volt meter in my dash rebuild. I wired it into a ignition switched fuse block terminal Realize that electrical problems with gauges is small but as I had unused fuse terminalson the block decided to wire it accordingly. Will have to put the VOM in series with the gauge to determine the amp rating for the fuse

David B Dixon
Port Perry ON CA
Sabine

[Tom Vilardi]

Thanks Court and Toller,  

Leaving it alone for right now (been checking regularly) and the pointer still stays at 13 volts but I worry that there will be an eventual drain.  

Funny thing is that I tried to attach the ground to a portion of the GM engine block that already had what looked like a ground fastened to it (still a newbie and learning about fiberglass/steel issues) and the gauge would not work until I put it into the negative battery post.  

If the gauge is lower tomorrow I’ll disconnect and eventually re-connect when I have more time (and the weather warms a bit).

Tom 

Tom Vilardi
BCW Model 52
South Orange NJ

[edward ericson]

Take the gauge off the battery, as instructed.

Also: ground your engine to the chassis. Put a steel strap or a bit of thick copper wire from the block to a frame rail. Bolt and washer or a sheet metal screw. Put a little grease on it to keep the rust off the metal where the paint’s scratched off to make the connection. 

[Tom Vilardi]

It’s 6 AM – checked Volt Gauge and it still sits at 13.  

That’s about 18 hours since it went in and I think an indicator that the Guage is just providing a reading and not drawing anything from the battery.  

It is analog, but if it had been digital I think there would be a drain.

So for now (unless someone thinks something catastrophic will occur) I will leave it alone until I can get back under the dashboard, make sense of what’s there and reconnect.

Thanks for all your comments and advice.

Tom

Tom Vilardi
BCW Model 52
South Orange NJ

[billnparts]

Your volt meter should drop to “0” when the key is off.

Bill Ascheman
Fiberfab Ford
Modified 5.0, 5sp., 4:11
Autocross & Hillclimb
"Drive Happy"

[Tom Vilardi]

It’s wired directly to the battery (both hot and cold) so it maintains a steady read of the voltage – does not drop to zero when engine is off 

Total hack job I know, but it is the only way I was able to get a reading on it in real driving conditions without starting to cut wires under the dash and potentially doing more harm than good.

I’ll eventually re-wire, but until I spend an afternoon under the dash getting a better understanding how it all fits together, this will have to do.  If I notice the volts dropping below the steady 13 they have remained at with the engine off (about 22 hours now), I will disconnect, but I think the analog volt gauge is not pulling anything from the battery and just providing a reading of what’s in the battery.

With the engine running the Volt Gauge immediately goes up to the 14-15 volt range as it should.

Tom

 

Tom Vilardi
BCW Model 52
South Orange NJ

[Author]

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