please help w/voltmeter use, picture included

[need boost]

Here is the easiest way to find a short that I have found, you can use your meter set to 20 vdc if you want or the easy way is just use a test light. Ok , unplug your orange comp plug by the battery first. Take off the negetive post and lay to the side . Now take one end of meter lead [ black ] or the wire from your test light and clip it on the negetive battery wire you just took off. Take the other end and clip, [vice grip, etc.] it to the battery negetive post itself. Now if you have a drain the meter will be reading it or the test light will be lit up. Get someone to stand up there and tell you whats going on so you don't run yourself to death. Open the drivers door and start pulling fuses one at a time till the light goes off or the meter reads very low. Remember you will have to hold the door plunger in so your interior lights are not on. When it goes off see what fuse it is and what it controls. Example would be radio. Ok now you know your short is in that wiring so you can find it without chasing all over the car . Good luck
oh and a short course for you is vdc= volts dc whats in a battery, ohm= resistance, no voltage or you will blow the fuse in the meter! vac= volts like whats in your house, aac= amps in ac voltage [ house power] adc amps dc voltage [batterys] on each one a=amps ma=milli amps [very little power] hope that makes it a little clearer for yah. We all had to learn it at one time or another lol. Good luck Daniel Ray

 

[Quick6'n'-K.C.]

Have you checked the trunk light to see if it is staying on all the time.
Have you unplugged the FAN ITSELF to see if its spilling electrons?

So much easier when you unplug stuff and using the meter.

BW

 

[TulsaGN]

Here is the easiest way to find a short that I have found, you can use your meter set to 20 vdc if you want or the easy way is just use a test light. Ok , unplug your orange comp plug by the battery first. Take off the negetive post and lay to the side . Now take one end of meter lead [ black ] or the wire from your test light and clip it on the negetive battery wire you just took off. Take the other end and clip, [vice grip, etc.] it to the battery negetive post itself. Now if you have a drain the meter will be reading it or the test light will be lit up. Get someone to stand up there and tell you whats going on so you don't run yourself to death. Open the drivers door and start pulling fuses one at a time till the light goes off or the meter reads very low. Remember you will have to hold the door plunger in so your interior lights are not on. When it goes off see what fuse it is and what it controls. Example would be radio. Ok now you know your short is in that wiring so you can find it without chasing all over the car . Good luck
oh and a short course for you is vdc= volts dc whats in a battery, ohm= resistance, no voltage or you will blow the fuse in the meter! vac= volts like whats in your house, aac= amps in ac voltage [ house power] adc amps dc voltage [batterys] on each one a=amps ma=milli amps [very little power] hope that makes it a little clearer for yah. We all had to learn it at one time or another lol. Good luck Daniel Ray

OK...I hooked it up your way with the multimeter, orange wire unplugged, and it is reading 12.45v. I tried to hook up my light under hood( I keep it unplugged until I need it) and it would not light up and no volt change. When I tried to turn on the dome light switch on the dash(didn't light) the volts would go up by .01 to 12.46v. Keeping the multimeter hooked up the same way, I switched it to read mA and it reads between 8 and 10mA, flickering back and forth. I hooked up the under hood light and it comes ON. When I tried dome light in car( it came on too) the meter would just say OL(overrange indication). Please explain these things to me. Thanks!

 

[Blown&Injected]

sounds like the connections were not good - use the 20 volt DC just about everything you measure is going to be much higher that mV ranges.

If you have the underhood light hooked up and it is on, it will show on the meter as a draw.

 

[TulsaGN]

sounds like the connections were not good - use the 20 volt DC just about everything you measure is going to be much higher that mV ranges.

If you have the underhood light hooked up and it is on, it will show on the meter as a draw.

I tried again with what you just said and the hood light WILL NOT come on if I have the meter set up for V. I tried all my connections every way I could and tried all ranges in volts and NO LIGHT and no draw. The reading I get is 12.5V, the exact same reading I get when I just check the volts of the battery itself. If I switch the meter to mA everything works, underhood light, interior lights, etc, but the meter will go to OL meaning out of range for that setting. I hate this and I don't understand. What is the deal?

 

[TulsaGN]

Well, with the orange wire unhooked and going in between the neg. battery cable and the neg. post and the Fan Delay Relay off, I'm only getting 8-9 milliampers. When I hook up the orange wire the milliampers go up by 2, reading 10-11mA. I'd say that's a very low draw, yes? Can somebody confirm these numbers and my thoughts. Thanks!

 

[David65]

Well, with the orange wire unhooked and going in between the neg. battery cable and the neg. post and the Fan Delay Relay off, I'm only getting 8-9 milliampers. When I hook up the orange wire the milliampers go up by 2, reading 10-11mA. I'd say that's a very low draw, yes? Can somebody confirm these numbers and my thoughts. Thanks!

10 to 11 mA's? Yes, that's very low, but that is good. The lower the better. For reference that is 0.010-0.011 Amps. With a discharge rate like that the battery should still be able to start the car after weeks of setting, if not a month or more. I asked a friend at the dealer once what my Blazer would be if I measured that. The answer was 30-40mA.

David

 

[David65]

I tried again with what you just said and the hood light WILL NOT come on if I have the meter set up for V. I tried all my connections every way I could and tried all ranges in volts and NO LIGHT and no draw. The reading I get is 12.5V, the exact same reading I get when I just check the volts of the battery itself. If I switch the meter to mA everything works, underhood light, interior lights, etc, but the meter will go to OL meaning out of range for that setting. I hate this and I don't understand. What is the deal?

The light shouldn't come on if the meter is set to read Volts and it is between the battery cable and the battery. In that condition, the meter has to be set to Amps to read the current flowing. If set to Volts it would read close to the battery voltage because the combined resistance of everything in the car is extremely low compared to the input resistance of the meter. When you set the meter to Amps, put the red lead in the 10 A spot to start with. (and remember to NOT put both leads on the battery at once or you'll blow the meter and or it's fuse) When it's set to read amps, it's input resistance is extremely low. Think of it like a piece of wire inside there. The meter reads the voltage across that (it's called a current shunt, btw) and displays the appropriate reading on the display because it knows what that resistance is and does the calculations.
The meter reads OL when it's being overranged, change to a higher range setting. That's why I would start out in the 10A setting. The underhood light should draw something like 100-150mA maybe, I've never measured it though. The interior lights maybe 200-300?.
If the battery is being drained really quick, something is drawing a lot of current. Even with the meter on the 10A setting, you might blow its fuse.

Sorry for the book...

David

 

[need boost]

Thats right. The light should not be on. What you see on the meter is the draw it is trying to take to light itself up. Think of it like this, 12.4 volts showing on the meter. Ok thats what its trying to take to run whatever is trying to run on the car. Pull fuses out till it drops down. When it does that circuit is where your problem is. Good luck Daniel Ray