Flapjack
Lunatic engine swapper
Let me preface this by saying, I consider myself to be a pretty decent electrician. There has been nothing I could not wire up in my car, house, etc... plus, I spent 10 years of my USAF career doing most of the electrical work in my fuel systems maintenance job (mostly 200-400 VAC, but also a lot of DC control voltage work as well).
I've used clamp-on ammeters in the past, but almost exclusively to check up on centrifugal fuel distribution pumps. These things put out anywhere from 300-600 gpm of fuel and drew quite a lot of amps. I'd use an ammeter to determine whether or not the motor before the pump was going bad (usually the windings).
So today, I go to pick up a Sears ammeter to help me troubleshooting a persistent battery drain my on 1997 Suburban. In the past, I've just disconnected a cable from the batter and jumpered the battery/cable to chase down current draws. I pull fuses to find where the draw is, which has worked every time. In the case of my Suburban, I was very little draw (in the neighborhood of hundredths of an amp). I've already had the battery and alternator checked. I don't drive the truck often, but I cannot leave the battery connected for more than a day or two without the battery being dead. I've replaced the battery twice.
Anyways, I ordered the ammeter online from Sears for in-store pickup. I screwed up and got an AC only one. Before I returned it, I had to try it out (of course). The first thing I tried was a lamp. It bounced between 0.02-0.03 amps. Finding that weird, I tried other things (TV, humidifier, obnoxiously bright halogen lamps in the garage, etc...). All read the same. So not only did I get an AC-only ammeter, I figured it was defective.
Later on, I switched for the next model up (link here) which does both
AC and DC. I read the manual, just to make sure I wasn't doing anything wrong (clamp works for both AC and DC... some only the leads work for DC, so I had to be sure). Same freaking thing. 0.02-0.3.
I tried the DC one using my phone charger which is rated at 1300ma (charges the high end "droid" phones very quick). My phone was nearly dead. I plugged it in and finally got the darn gauge to change (a little). It read 0.08 on the 40amp setting. Still, I know from reading on various phone forums that you can't use a crappy charger with these phones because they can pull over an amp while charging.
The final test, to make sure I wasn't crazy was to single out the highest amperage thing in the house... the dryer. I put it on the 40amp setting, as the label said ~30 amps at load. The reading on the meter? 0.02 amps.
So my question is... what am I doing wrong? Is it really possible that I bought two defective ammeters in a row??
I've used clamp-on ammeters in the past, but almost exclusively to check up on centrifugal fuel distribution pumps. These things put out anywhere from 300-600 gpm of fuel and drew quite a lot of amps. I'd use an ammeter to determine whether or not the motor before the pump was going bad (usually the windings).
So today, I go to pick up a Sears ammeter to help me troubleshooting a persistent battery drain my on 1997 Suburban. In the past, I've just disconnected a cable from the batter and jumpered the battery/cable to chase down current draws. I pull fuses to find where the draw is, which has worked every time. In the case of my Suburban, I was very little draw (in the neighborhood of hundredths of an amp). I've already had the battery and alternator checked. I don't drive the truck often, but I cannot leave the battery connected for more than a day or two without the battery being dead. I've replaced the battery twice.
Anyways, I ordered the ammeter online from Sears for in-store pickup. I screwed up and got an AC only one. Before I returned it, I had to try it out (of course). The first thing I tried was a lamp. It bounced between 0.02-0.03 amps. Finding that weird, I tried other things (TV, humidifier, obnoxiously bright halogen lamps in the garage, etc...). All read the same. So not only did I get an AC-only ammeter, I figured it was defective.
Later on, I switched for the next model up (link here) which does both
AC and DC. I read the manual, just to make sure I wasn't doing anything wrong (clamp works for both AC and DC... some only the leads work for DC, so I had to be sure). Same freaking thing. 0.02-0.3.
I tried the DC one using my phone charger which is rated at 1300ma (charges the high end "droid" phones very quick). My phone was nearly dead. I plugged it in and finally got the darn gauge to change (a little). It read 0.08 on the 40amp setting. Still, I know from reading on various phone forums that you can't use a crappy charger with these phones because they can pull over an amp while charging.
The final test, to make sure I wasn't crazy was to single out the highest amperage thing in the house... the dryer. I put it on the 40amp setting, as the label said ~30 amps at load. The reading on the meter? 0.02 amps.
So my question is... what am I doing wrong? Is it really possible that I bought two defective ammeters in a row??