Installing duel volt meters... update 9/7

[kaptnkaos]

I bought a pair of matching volt meters for the '68 CS...
I want one to read the main battery and the other one to read the aux battery for the camper.
How would be the best way to hook them up? I have an idea, but I'm not 100% positive and don't wanna do sumthin' stupid and burn stuff up...
What gauge wire would be the best to use... I have heard that you don't need as heavy wire for a Volt meter as you do for an amp gauge..
Anyone know the skinny on that?

Thanks again,
KaptnKA S

[Thunderfoot]

16 Gauge wire should be good, it doesn't draw hardly any current. You will want to switch them somehow so they are not on all the time... For the main battery you can hook it into any switched wire like the radio, it may show a little less then reading directly off the battery but will be close enough. For your camper battery you are probably going to have to run it to the battery... You don't have to run the ground to the battery's unless you have the camper ground isolated from the rest of the truck for some reason.
All they are is just a meter like your test meter just don't have all the other stuff, it just reads the voltage only.

[kaptnkaos]

Yeah Thunderfoot...

That's exactly the way I wuz picturin' doin' it.
I was gonna run a (+) wire from the keyed side of the new fuse block to the (+) side of the meter and one to ground. The 3rd wire for the lights will go to the feed for the dash lights.
WIll I need to install a relay for that ?
The one thing I wasn't sure about was how to deal with the one for the aux bat since it's hot all the time.

KaptnKA S

[stephen44]

I do something similar on my RV - but i use only one meter -

i have a switch that selects which battery (i.e. hot cable).

The switch i bought is a sprung switch so it is on the car battery all the time and is switched (not on when car is off) and the sprung or momentary side shows me the camper battery -

it can not be left in the 'on' position all the time. I find this worked great and i can't get a dead battery !

Stephen

[george worley]

I have a volt meter in my truck,+ wire hooked to radio wire I grounded it to the dash, I hooked the light up to dash light fuse. I didn't need a relay in my case.

[Thunderfoot]

Stephen, good idea

Kaptn, you shouldn't need a relay for the instrument light, it should be OK just tapped in.

[kaptnkaos]

Hey guys,

What about using a switch like this with one meter...
That way when it's off there isn't any power going through the meter all at all




KaptnKA S

[stephen44]

The only problem is that you could leave it on and drain the battery.

But yes - this would work - I would prefer you to use a momentary on switch like:

http://www.radioshack.com/product/index ... Id=2062530

[kaptnkaos]

Hey stephen44,

I'm seriously considering going with my original plan of having two meters.
one for the primary and one for the auxillery circuits.
I have one of the white F600 panels which would look better with two (one on each side).
That way I would know exactly what's happening with both circuits.
It would also act as a reminder if something is left on in the camper... like a light or the fridge.
If nothing is on, on the auxillary circuit, would the gauge itself draw power???

KaptnKA S

[stephen44]

Over time a volt meter will make your battery go dead. You could use a relay where the switched - car voltage energizes the relay passing the camper voltage through to the meter - I agree in a F600 cluster - 2 gauges will look great. You could probably find a relay that has two switched sides - one for each meter - I'm sure you could find this in a wreckers yard.

[flyboy71]

You could install a master relay right off the positive battery terminal and totally disconnect your battery from everything. Grounding the control pin energizes the relay, plus its continuous duty. They use these in aircraft everywhere as a battery disconnect. http://www.aircraftspruce.com/catalog/e ... rrelay.php

[stephen44]

You could install a master relay right off the positive battery terminal and totally disconnect your battery from everything. Grounding the control pin energizes the relay, plus its continuous duty. They use these in aircraft everywhere as a battery disconnect. http://www.aircraftspruce.com/catalog/e ... rrelay.php

I like that idea - it doesn't say what the current rating is though /??

[flyboy71]

That I dont know off hand but I can tell you, the starter solenoid connects on the other side of it so it gets the full current of starting and powering the airplane. If I had my Cessna service manual handy I could look it up.

[kaptnkaos]

Now you guys are talkin' way over my head...
Does the meter itself draw power?
When I got my truck 22 years ago, it had a duel battery setup.
2 batteries, 1 alternator, and 1 battery isolater...
I used it like that for several years and never had any problems with dead batteries.
As of right now, I have it set up the same way, except everything is new.
Everything seems to work fine if I using it during the day.
It's driving at night like I usually am on the way home from an event.
The next morning both batteries are low and have approximately the same amount of charge in them.
I was gonna replace the master cylinder, 'cause it was leaking last weekend and take it Shucks and have the charging system checked out, but broke a brake line so I 'm kinda dead in water until I can get that fixed.
The meters are an after thought, but would really like to know whats going on with the system...
The amp gauge isn't working on the F600 panel, but it didn't work on the original cluster either.
This is part of the reason I want to install the volt meter.
If I hook up one meter to a keyed power feed and ground, that would read the primary battery circuit right?
Now, to hook up the meter for the aux battery circuit.
If I run a positve wire from the aux battery to a toggle switch then to the meter, then ground it, the meter would only be on when the switch is on.
I was looking at the solenoid, and couldn't figure out how that would work. I'm not much of a Sparky, but I'm learnin'.
An idea I had to remind myself that the switch for the meter was on, was to feed the meter light from the switch. Anytime the switch is on, the light would be on as well. It would stay on even when the key is shut off.
I'm just thinkin' that the alternator isn't putting out enough power to run the fridge, the head lights, and the stereo at the same time.
On the way to an event, only the fridge and the stereo and amp is running, one way home headlights are added to the equation. The alt that's in it now is a 65 amp.

I appreciate all the input..

KaptnKA S

[stephen44]

so you need to see if both batteries are getting charged by the alternator ?.

The switch idea will work for the house meter- it is up to you to remember to turn it off - use the sprung switch and it can't stay on - they call it a momentary switch - radio shack sell a ton at $2.00. Power the main one via the switched battery side and you will be good to go.

The voltmeters will draw power although a minuscule amount