Voltage Drop Question

[danteBirosel 5,000+ posts]

I was wondering what are the signs that i would be getting if i am getting voltage drops? how will i know i am recieving them?

i have only done only one step of the big 3. which was the battery negative to the chassis ground.

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[bikejunkie223 10+ year member]

You can easily test for voltage drop with a multimeter. Measure voltage at one point in the circuit, and then measure it farther in the circuit, the difference between the 2 voltages is your voltage drop, and should be minimal (i'm assuming you are talking about your amp power wire), so check for voltage at the fuse by the battery. write that reading down (it should be about 12.6v with the car not running. Then check voltage at the amp input. should still be very near 12.6v, if it's lower, you have unwanted resistance between the 2 points (bad wire, poor contact at the fuse, poor wire contact in a fuse holder) Hope that helps.

 

[Meankid420]

ya i would use a volt meter would be the easiest way to do it

 

[liar2 10+ year member]

I would say headlight dimming is a good sign of voltage dropping

 

[danteBirosel 5,000+ posts]

You can easily test for voltage drop with a multimeter. Measure voltage at one point in the circuit, and then measure it farther in the circuit, the difference between the 2 voltages is your voltage drop, and should be minimal (i'm assuming you are talking about your amp power wire), so check for voltage at the fuse by the battery. write that reading down (it should be about 12.6v with the car not running. Then check voltage at the amp input. should still be very near 12.6v, if it's lower, you have unwanted resistance between the 2 points (bad wire, poor contact at the fuse, poor wire contact in a fuse holder) Hope that helps.

great info! thanks. so i should test it whiel car is off right? red connector on the wire and the black on any ground? DCV setting? ok thanks.

 

[CntInjaDisNinja 10+ year member]

I got a $15 volt gauge at an auto store, connected it to a fuse in my fuse box under my sterring wheel, up to the second voltage drop, accurate to about .1 volts(testes with DMM), its cool cuase the needle bounces with the bass

 

[bikejunkie223 10+ year member]

great info! thanks. so i should test it whiel car is off right? red connector on the wire and the black on any ground? DCV setting? ok thanks.

You can test it with the car running, or not, the only difference is the alternator raising system voltage to around 14.5 volts, rather than 12.6, though the same testing method still applies, any difference = voltage drop. To the guy that said a volt-meter, that's what a multimeter is, it does voltage, resistaance (ohms/continuity) and often amperage, all in one tool, so it is far more versitile than just a volt-meter.

 

[CntInjaDisNinja 10+ year member]

You can test it with the car running, or not, the only difference is the alternator raising system voltage to around 14.5 volts, rather than 12.6, though the same testing method still applies, any difference = voltage drop. To the guy that said a volt-meter, that's what a multimeter is, it does voltage, resistaance (ohms/continuity) and often amperage, all in one tool, so it is far more versitile than just a volt-meter.

yeah a DMM is very vesatile, but what I meant is it is an actual analoug gauge mounted on my dash so I know my voltage when I driving down the road, its pretty nice cuase you see slight voltage drops like when turning on the lights or even putting down a power window, plus it adds a little looks to the interior

 

[bikejunkie223 10+ year member]

yeah a DMM is very vesatile, but what I meant is it is an actual analoug gauge mounted on my dash so I know my voltage when I driving down the road, its pretty nice cuase you see slight voltage drops like when turning on the lights or even putting down a power window, plus it adds a little looks to the interior

Gotcha, I just hate having needles and stuff flashing as I drive. I hate all the retarded movies on my head unit, but I get what you are saying.

 

[Chevyaudio 5,000+ posts]

I have a digital voltage meter mounted right under my HU, All it really does is distract me, and everytime some new girl gets in my truck I have to explain what it is.