Factory voltmeter: Useless?

[hatedonmostly 5,000+ posts]

I've always wondered if the factory voltmeter in the gauge cluster is actually useful or not. I have a 90 amp alt in my '98 Dakota, and no matter what, the voltmeter sits at the same level. I can be wangin', or just sitting, it always sits at 14 volts.

But then again, I've only got 900 watts going to my subs.

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[KyleBechtold 5,000+ posts]

how about when the car is off but acc are on?

 

[hatedonmostly 5,000+ posts]

Not ACC (when the car is in ACC mode, the gauges aren't affected whatsoever, but you probably knew that), but when the key is put to the ON position, it does indeed differ then. ON is about 12.6, or whatever it should be.

I'm just talking about when the car is running or in ON, no amount of power being used affects the gauge.

 

[BassAddictJ 5,000+ posts]

get ahold of a dmm and test it to see if the voltage is consistant with the dash voltmeter. that dash voltmeter should be hooked up to the ignition positive, which is just fine to use to monitor voltage.

If you have no electrical upgrades i'd imagine you'd still drop close to 12v even with only 900w. there's a good chance the voltmeter is crap. If thats the case you can likely find a cheap voltmeter to go in its place and have a nice digital read out in it's spot //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[KyleBechtold 5,000+ posts]

even if you flip the ac on it doesn't budge? it should atleast twitch..

 

[hatedonmostly 5,000+ posts]

get ahold of a dmm and test it to see if the voltage is consistant with the dash voltmeter. that dash voltmeter should be hooked up to the ignition positive, which is just fine to use to monitor voltage.
If you have no electrical upgrades i'd imagine you'd still drop close to 12v even with only 900w. there's a good chance the voltmeter is crap. If thats the case you can likely find a cheap voltmeter to go in its place and have a nice digital read out in it's spot //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

No electrical upgrades. Why would it drop to 12V, this I don't understand. Doesn't a car run at 14.4?

I guess I was assuming it would be off because it's a factory gauge. We all know how accurate speedometers are. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

I was considering getting a nice digital readout, but I don't have enough power or anything to worry about it. Though I'll do the Big Three someday, just for peace of mind.

even if you flip the ac on it doesn't budge? it should atleast twitch..

I don't ever have my A/C on.

 

[BushJ311 5,000+ posts]

Not sure about yours but in my blazer it seems to work fine and read about the correct numbers

 

[hatedonmostly 5,000+ posts]

Guess I might have just jumped to conclusions, and should have stuck with my original theory that my system doesn't require enough power to affect the electrical.

 

[BushJ311 5,000+ posts]

Even when my ac is on or a turn signal it moves a little bit.

 

[hatedonmostly 5,000+ posts]

I don't ever remember mine ever being that sensitive. I'll give things a look over tomorrow.

 

[BassAddictJ 5,000+ posts]

your alty and battery are only made to put out enough power for the car and maybe a tad but more. when you start drawing 900w off it it should make the voltage drop. It shouldn't stay at 14.4v. I'd guess it'll drop down to around 13v, maybe less. If it goes under 12v then i'd be worried.

get ahold of a dmm and see if the dash gauge is accurate.