Installing a voltmeter, and a question

[aldente295]

I've just completed installing a voltmeter into the dash of my beloved Brian. I was prompted to do this after a dead alternator left me stranded awhile back.

The install wasn't 'hard', and was cheap ($20 VDO voltmeter on ebay plus some wire) but took quite a lot of time from start to finish. I'd give the final result an 8 out of 10, mostly because of the hazard switch issue that I experienced...





I'm very pleased with how the voltmeter turned out (got the idea from someone else's photo here) but the hazards were a bit disappointing. Because of the length of the hazard switch, when I inserted it into the new hole I'd made on the right of the steering column, it hit the heater cables behind the dash, which means the switch doesn't sit flush with the dash.



It's hard to see and I don't think anyone but me will notice it, but it's a shame nonetheless. I may look at finding a collar or something to make it look more 'finished' - the challenge is that there's a pre existing hole that I used, so it kind of has to go in this location - moving it an inch lower would have looked strange.

Anyway, my question - when I hooked up the voltmeter, I used one of the connections in the hazard switch itself for the power. (I made a short 'wiring harness' to extend the wiring from the existing location to the new one, and just split one of the connections). The connection I chose is always 'on', which means the voltmeter is too. Do you think this will draw a significant amount of power? Would I be better off finding a connection that is only live when the key's turned?

Cheers
Al

[James Brown]

your good, any 12v source will work

[timmy2]

If it were me, I'd connect to a switched hot for the meter (ignition switch is right there) and figure out some sort of bezel extender ring for the hazard switch. Make sure nothing is touching the heater control cables back there. I had an A/C control switch there installed by the PO, I removed it when I saw sparks dropping at my feet! There is a nice small rocker switch there now for a blower fan.

[911pcars]

Originally Posted by timmy2

If it were me, I'd connect to a switched hot for the meter (ignition switch is right there) and figure out some sort of bezel extender ring for the hazard switch. Make sure nothing is touching the heater control cables back there. I had an A/C control switch there installed by the PO, I removed it when I saw sparks dropping at my feet! There is a nice small rocker switch there now for a blower fan.

A good voltmeter will have high impedence, that is, high resistance to current flow through the meter. Typical aftermarket gauges usually aren't that sophisticated, thus I'd connect to the cigarette lighter or other circuit that activates when the ignition is ON.

As for the protruding switch, a simple bezel extender could be some stacked washers/spacers or equivalent.

Sherwood

[mreid]

You will be surprised how much current it will draw. It needs to be on switched power. Use the gauge power wire from one of the other gauges. That way it's also fused as intended.

[McLaren-TAG]

I was wondering why the picture shows 12 volts on the gauge and your comment about it being wired to a constant explains it.

[Justin@Athens]

I would just create a "bezel" of sorts to go around the new hazard switch. Some kind of black ABS plastic pipe in the correct diameter cut to a width of what looks to be about 6mm. Or as another op suggested, try to relocate that switch and put another "shorter" one in its place.

[kuehl]

One of these always comes in handy;
this model allows you to swivel the head so its easier to view.

[Joe Bob]

Switched power is best. You WILL get a bit of a drop, check the differential with a meter to the battery and the posts on the alternator.

I hooked mine up originally straight to the battery, there was enough of a draw to kill it after a week. Airplanes turn the gauge power off due to extended down time.

[aldente295]

Originally Posted by Justin@Athens

I would just create a "bezel" of sorts to go around the new hazard switch. Some kind of black ABS plastic pipe in the correct diameter cut to a width of what looks to be about 6mm. Or as another op suggested, try to relocate that switch and put another "shorter" one in its place.

The plastic pipe idea is excellent - I'll have a look in the hardware store.

I'll find a nearby source of switched power and swap it over - thanks all.

[dshepp806]

As close as you can get to the battery (switched) is best..I wouldn't "share" any circuits if possible.

Best!

Doyle

[maui44]

+1 kuehl cheap and easy installation. Also, who use the lighter outlet anymore?

More bucks however, you can have your oil level gauge switched out to a volt meter.

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