Did I get a bad Multi-Meter??

[doonze]

So I was out at Harbor Freight for the first time last week. Don't laugh, I always thought it was a Furniture Store... There's a story as to why, but I won't go into that now.

So anyway, I'm looking at Multi-Meters... And as luck would have it they are on sale. I find 1 I like and it's a grand total of $3.99... but it test 7 things so woo hoo, score!

So today, I'm out reading some codes and decided to try out the MM, just to make sure it works and all, so I put the correct leads on the battery, truck off, and it reads..... 15.39 Volts.... WTH?

Is that even possiable?

Remember.... truck OFF, NOT RUNNING..... Going to test some more stuff later.... but wow! I think I may have a bad MM.

 

[shaggymane]

so I put the correct leads on the battery, truck off, and it reads..... 15.39 Volts.... WTH?

Is that even possible?

Remember.... truck OFF, NOT RUNNING..... Going to test some more stuff later.... but wow! I think I may have a bad MM.

What's that saying? Anything's possible, however, not very probable.

And why there return policy is so liberal...... *could be better quality control*.

Got any 9v battery's around, smoke detectors and such? String some AA battery's and measure, 1.5, 3, 4.5, you know how.

 

[BrooklynBay]

Your battery with the engine off should be around 12.5 volts. Do you have it in the correct range (assuming that it's a manual range meter, and not an auto range meter)?

 

[dkchrist]

that is a lot of volts. Normally once a battery reaches its rated voltage they are somewhat discharged but that is unreasonably high. Maybe 13 volts at the most on a brand new battery.

 

[TedJ]

Not possible that a 12v battery is putting out 15v. With the engine running its possible (alternator charging) but otherwise not.

I'm assuming you got one of those little orange cen-tech ones, either with or without the backlight. First check that the 9v battery inside is good and that a battery symbol is NOT displayed. Low batteries can make multimeters do weird things.

Make sure your black lead is in the com hole, and the red one in the volts/ohms/ma hole. Set it to 20v in the DCV range (which is on the top left).

If it still reads 15 or so, bring it back for another one. I own both the non backlight and backlight versions, as well as a really expensive fluke meter. In comparing them, while it takes a good bit longer for the HF ones to stabilize at a voltage reading, they are within .1v + or - of what the fluke reads, which is definitely good enough for basic auto repair. They are good especially at $4, I think you might have just gotten a defective one.

 

[Maniak]

<snip>

If it still reads 15 or so, bring it back for another one. I own both the non backlight and backlight versions, as well as a really expensive fluke meter. In comparing them, while it takes a good bit longer for the HF ones to stabilize at a voltage reading, they are within .1v + or - of what the fluke reads, which is definitely good enough for basic auto repair. They are good especially at $4, I think you might have just gotten a defective one.

Ditto on that.. I have 4 of so HFT ones now, plus my good one.. I rarely take the good one out. I found it is cheaper for me to buy another HFT one when its on sale and using a coupon than it is to replace the battery..

The only drawback I've seen on the HFT ones is as already mentioned, slow to show the voltage (hard to use on fluctuating voltage) and it takes longer for it to check for a short than my good one.

BUT, I won't use my good on to check DC amps and I have no problem putting the HFT one inline to check something that might pull upwards of 20 amps.. It won't bother me too much if the HFT lets the magic smoke out when I run too many amps through it..

~Mark

 

[TedJ]

I get the HF ones for exactly the same reason, they're basically disposable. A meter is handy to have around for testing batteries, checking cables, etc and nothing beats having one when you need it. The only problem I have had is the battery going dead from the switch getting pushed to the on position when it was bouncing around in my bag.

I don't think you can let the magic smoke out too easily, IIRC there is a fuse in there, I think they need to have it because imagine if you overloaded it and the leads melted... can you say lawsuit

 

[doonze]

Yeah, I was pretty sure something was going on with the MM, I was just double checking I wasn't missing something here. The battery symbol IS on, it was like that out of the box. I might try a different 9v and see how it goes! Thanks for the input guys.

 

[TedJ]

Try a new battery, they get real funky when the battery light is on...

 

[doonze]

Just an update, got a 9v and tried it out today... problem fixed! Before both cars read 14-15 VDC. After replacing the 9v with a new one, 12.84.... On both cars!!

On a side note, plugging the red cord into 10AMP, and and trying to see if you have a current draw is a bad idea. I involves melted, smoking, probe wires and a smoking MM.

On a up note, the meter still works, once it stopped smoking.

Now to figure out the CORRECT way to test what I was trying to test. My way was for sure the WRONG way....

Now where did I put those instructions....hmmmm.....

 

[BrooklynBay]

Thanks for the update! You have to open the circuit, and connect the meter in series to measure current draw. One easy way to do it is to remove the fuse, and connect the meter where the fuse would normally go.

 

[Maniak]

On a side note, plugging the red cord into 10AMP, and and trying to see if you have a current draw is a bad idea. I involves melted, smoking, probe wires and a smoking MM.

On a up note, the meter still works, once it stopped smoking.

I'm glad to see I'm not the only one to let some magic smoke out.. they are supposed to be fused, but it never seems to pop..

BTW.. you were doing it right ot check for current draw (parasitic). It goes between the battery and a batter terminal.. BUT.. you should be checking with everything off, which means all doors closed and the hood lamp off (if it has one)..

~Mark

 

[doonze]

Ahhh.... IC...

Yeah, I just stuck it between the battery terminals... oops.

Now I'm getting the idea I think...

Did read like 17AMP before I realized it was on fire.....

One probe looks like I was using it to solder....

And the wire insulation was so hot it was gooey....

The really cool part is the MM is fine!!! HA, maybe a $3.99 cheapy, but I just caught it on fire and it STILL works!!! Go HARBOR FREIGHT!! LOL