How to test Supply Voltage.

How to do a supply voltage test on a car circuit. Please like and follow for more content.

Transcript

00:00Hi everyone just a quick video on how to do a supply voltage test so what is the supply

00:05voltage test it's making sure the voltage from the battery is getting to that component so it

00:09should be working so it could be a bulb or a motor or anything like that so I'm going to do a bulb

00:14as a demonstration just because it's nice and easy and simple to understand so first of all

00:18got a multimeter set to 20 volts DC because it's never going to be greater than that because the

00:23battery voltage is 12.6 volts on this particular car so if it's a 12 volt system like this one

00:29it's a 12 volt bulb I don't want to see any more voltage loss than one volt so this should be a

00:34minimum of 11.5 volts if I was dealing with a sensor that runs on six volts then obviously it would be

00:39half a volt I'd be looking for maximum in terms of lost uh voltage through the connectors and the

00:45terminals and the fuse and so on so first of all you need to turn on the system that you want so

00:49I've turned on the headlamps for this particular car and then I've unplugged it so I've got my uh

00:53connector here for the headlamp bulbs uh so what I'm going to do is with my multimeter I'm going to

00:58get my negative lead and with the one hand I'm going to place that into the this particular

01:05connector and that's in there and then I'm going to get my other positive probe I'm going to put it

01:11into that connector there make sure the system's turned on as I say otherwise you'll get no reading

01:14so as far as this connector is concerned it's already plugged into the back of the bulb so

01:18the voltage coming to the back of that bulb is 11.91 volts so as I say it's a 12.6 volt battery

01:25so that's well within the one volt uh expected voltage drop so I know for a fact that the fuse

01:30and all the associated wiring from the battery through the ignition the stalk inside the car

01:35all the way to the back of the bulb is uh within range so if the bulb's not lighting up which is

01:41this case uh this is the case with this car then the bulb itself must be at fault because everything

01:46running up to there is good sometimes you don't get a negative on the actual terminal it'll be earth to

01:51the body so therefore you'd find a screw or something that's mounted to the engine bay so you go positive

01:56on here and then a negative on the earth just to complete the circuit but in this case it's two

02:01connectors uh and I'm getting 11.91 volts so uh yeah wiring on this car is good so hope that makes sense

02:08and we'll see you on the next one

02:09and we'll see you on the next one

02:10and we'll see you on the next one

02:11and we'll see you on the next one