need a amp meter, gj recomendation wanted

[senor fozz]

i have to find a parasitic draw on a 01 lexus ls430. i installed a device in it. because the car has so much electronic **** in it i fear i would be putting my fluke in danger if i was to use it to check total current draw from the battery and since the car takes so long to go to sleep i would rather just put it on the battery and leave it while i do my testing.

needs accuracy i would be happy with 10 ma settle with ~30 ma. max amps ~50 or greater

can be stand alone would prefer something with a screen being seperate from clamp. something that plugs into a meter as long as it is accurate enough.

dont care about coo. lack of warranty okay if reflected in cost. budget less than 200 would prefer to be in 50 to 100 range.

 

[jkwilson]

Most meters will handle it with no issue as long as you don't crank the engine. The easiest way to go is to pull the negative battery cable and connect an ammeter between the post and cable. Pull fuses one at a time while noting the current. Many things draw current all the time, so it may take some thinking. I assume you've had the alternator checked?

 

[senor fozz]

i'm well aware of the method you are speaking of, the issue is this vehivle turns on so many lights(head lights, all 8 taillights not mention the interior functions) im willing to bet it can blow my fuse in the meter. i dint want to unplug or pull all the fuses for this car woukd rather just have something safer.

 

[Ruger_556]

Midtronics PDF40

 

[GTA Matt]

If you know for certain it has a draw, you can just check voltage drop across each fuse to determine how much draw is on that particular circuit and troubleshoot from there. Pulling fuses can be a bad idea as it can wake up a sleeping module when you reinstall the fuse and give you some false readings.

 

[Ruger_556]

What he said ^^^ Works great!

 

[senor fozz]

guys i have been wanting a clamp for years and i now have a legit reason to buy one so please indulge me i checked cl and nothing fits the bill.

 

[theoldwizard1]

GTC CM100 1 mA to 100 Amps AC/DC Low Current Clamp Meter

ESI 695 80 Amps DC/AC Low Current Probe

 

[bcradio]

guys i have been wanting a clamp for years and i now have a legit reason to buy one so please indulge me i checked cl and nothing fits the bill.

Don't do it man... PUT THE WALLET AWAY

On a serious note: I have a Fluke 376 and like it very much. I also have a low amp clamp on my 'to-get' list which would likely be ideal for you (GTC CM100).

 

[senor fozz]

of everything suggested so far i like the midtronics compared to the others based on the openning size. is the reason the gtc opens so little is to get better accuracy?

 

[Danglerb]

Sears Craftsman 82369 clamp meter, AC/DC amps and while it does "wiggle" a little and has some sensitivity to location, it does zero and track pretty well down to below 10 ma. Now that I have it, its my go to meter mostly due to the 5 secs needed to clamp on and measure current without cutting a wire or opening a connection.

Parasitic drains are a major issue on my old 928, so much so that both of mine have battery disconnect switches, not a great endorsement for my meter maybe, but its not one thing with my cars its whatever chooses to be a pain that day. Found and fixed drains a couple times, then put on the battery switches.

Testing my wife's 99 Continental and tracked each stage of the 30 minute or so "cool down" until draw was under 1ma.

 

[Danglerb]

Drain hunters also like the Fusebuddy, pull the fuse, put fuse in the tester which uses it, and a meter shows the amps. Any drain hunt eventually you are pulling fuses and testing circuit by circuit.

 

[bwringer]

Thanks for mentioning the Fusebuddy!

I had no idea there was an actual tool for this. I've made up little harnesses that do the same thing many times, but it sure would be a lot neater and a little safer to use an actual purpose-made device.

You learn something new every day, I guess.

 

[Tarheelgarage]

Get and install a battery disconnect switch and just measure the low amps draw across the open switch with your DMM. Way more accurate. Wait at least 30 minutes before opening the switch to allow modules to go to sleep.I have a SO low amp clamp but try to use this method as much as possible. I have an old SO Vantage that I use and am able to graph over time the current draw just to determine if some module might be coming on line after a few hours of being off.









As already mentioned, if you start pulling fuses, you risk waking up some modules. Use fuse buddies to help identify circuit with off draw issue.

Use a test light at fuses to determine which circuits are still drawing current
when they should not be.

 

[Danglerb]

Get and install a battery disconnect switch and just measure the low amps draw across the open switch with your DMM.

Good job for a free HF meter, but not something I would do with any of my decent meters, too many ways to fry or blow the internal fuse.

One of my drain pains, aftermarket alarm system likes to arm itself if the voltage drops and wiggles some, then triggers and toots horn and flashes lights, **** goes the meter fuse.

 

[GTA Matt]

Again, no good reason to be pulling fuses. If you're bent on getting a clamp, that's great, less evasive then installing a shunt and using the meter, even though that has been the method for many years, and when done correctly, no fuses will be blown. Use the clamp to determine draw, then use your DVOM to check voltage drop across fuses. Quicker then pulling fuses one by one and checking for current drop and no modules will be woken up. Set your meter to millivolt scale, it is obvious when you find the at fault circuit. No need to pull the fuse to see if the draw disappears either. You can already calculate the draw by the voltage drop. Killing power to a faulty module may 'fix' it temporarily when you plug the fuse back in. Then determine what exactly is on that circuit and access modules/components at their connectors. Since you have a clamp, you can be even less evasive and check the draw at the suspected faulty component without ever unplugging it. The key is to disturb as little as possible. BTW, all aftermarket components are the first things completely disconnected when tracking draws.

 

[vdt1977]

I've used the ES687 for years, and it works great, albeit the opening is a tad bit too small. The 688 is out now, and looks very promising, but quite a bit spendier (~$300). I'm looking to upgrade myself, and debating between that and the Midtronics unit now...

Will the Midtronics go down to 1 mA? (.001)

 

[bcradio]

Again, no good reason to be pulling fuses. If you're bent on getting a clamp, that's great, less evasive then installing a shunt and using the meter, even though that has been the method for many years, and when done correctly, no fuses will be blown. Use the clamp to determine draw, then use your DVOM to check voltage drop across fuses. Quicker then pulling fuses one by one and checking for current drop and no modules will be woken up. Set your meter to millivolt scale, it is obvious when you find the at fault circuit. No need to pull the fuse to see if the draw disappears either. You can already calculate the draw by the voltage drop. Killing power to a faulty module may 'fix' it temporarily when you plug the fuse back in. Then determine what exactly is on that circuit and access modules/components at their connectors. Since you have a clamp, you can be even less evasive and check the draw at the suspected faulty component without ever unplugging it. The key is to disturb as little as possible. BTW, all aftermarket components are the first things completely disconnected when tracking draws.

Good post Matt. Quick question: when performing the voltage drop on the suspected fuses, do you probe the fuse to ground?

Thanks for any help

 

[GTA Matt]

To do the voltage drop, just put one lead on each side of the fuse. If you are curious what it looks like, you can just try on on say, your headlight fuse, check it off, then turn them on and notice the difference. Again, set your meter on millivolts and not on 'auto' if your meter has that function. There are charts, I'm sure you can google them, if not I can take a picture of mine, that give a conversion for what current the voltage drop equals.

 

[00S4Boy]

http://www.tooltopia.com/amprobe-lh41a.aspx

got one of those as a shop tool at work works great.

 

[bcradio]

To do the voltage drop, just put one lead on each side of the fuse. If you are curious what it looks like, you can just try on on say, your headlight fuse, check it off, then turn them on and notice the difference. Again, set your meter on millivolts and not on 'auto' if your meter has that function. There are charts, I'm sure you can google them, if not I can take a picture of mine, that give a conversion for what current the voltage drop equals.

ahh ok, so the presence of any voltage across the fuse indicates current flowing through that circuit?

 

[GTA Matt]

ahh ok, so the presence of any voltage across the fuse indicates current flowing through that circuit?

Correct, a voltage drop indicates the circuit is 'working'. Similar to doing a voltage drop test on a starter cable while cranking, but on a much smaller scale.

Sorry for the thread jack, for the OP, I have both just a cheap stand alone otc clamp, and a snap on clamp hooked to my lab scope that I use for draw tests. Any $50-100 clamp will be fine for draws, getting down to .001 mA is splitting hairs and unnecessary for this.

Voltage drop/current scale