Location: Las Vegas, NV
Posts: 128
My VIN: Jan '82 #11153
Can someone recommend a volt/amp meter (make & model) to check the milliamps from the battery to try and locate what is causing the battery to die after 2 days? I'm just a dumb mechanical engineer and electrical is not easy for me. Any comments on how to use or be careful of is greatly appreciated. Don't want to burn it up the first try.
Location: Somewhere in the Ford Galaxy
Posts: 123
My VIN: 1561
Doesn't require anything too special, just put it in ammeter mode (with the leads in the correct sockets as well) and disconnect the + lead going to the battery. Connect one test lead to the battery + terminal and the other to the loose + battery cable. This will cause all current to go through the meter so it can be read. Most meters are fused to something around 10 amps. If you're pulling more than that with the car off something is terribly wrong. But even if you are you won't hurt the meter, just the internal fuse will blow.
Edit: as for a specific suggestions on a multi-meter. The one I use is probably over 20 years old and I'm sure not sold anymore. But I just found this on Amazon and seems to have decent reviews, but I don't have any experience with it. In the case of this one you'd put the test leads in the leftmost and rightmost ports and set the dial to the yellow "10" setting just past the 3 o'clock position.
One more edit: After you test directly at the battery and confirm if there's too much drain on the whole system you can reconnect the battery as normal. Then start pulling fuses one by one and put the test leads in the fuse socket (leave the meter on the same settings as before). This will cause just that one circuit to be read for current so you can narrow down your problem.
Last edited by todd1561; 11-30-2022 at 05:10 PM.
Location: North GA
Posts: 6,177
Club(s): (SEDOC) (DCUK)
An ice pick probe or taillight bulb in line with one of the battery cables should work...
Location: Olathe, KS
Posts: 1,680
My VIN: 11596
I don't have one yet, but I'm going to get one shortly - a clamp amp meter is super convenient for checking amperage. Extech MA120 is a pretty good value but only has resolution down to 0.1 DC amps. Good for finding large to medium amp draws but not quite sensitive enough for the tiny trickles.
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Andy Lien
VIN 11596 Jan 1982 build - owned since Nov. 2000!
Total frame-off restoration completed 2021-2023
Photography and Backpacking is life.
Was Fargo, ND
Now Kansas City
Posts: 448
I"m very pleased with this one. It's small and reads DC down to milliamps.
Ron
https://www.amazon.com/gp/product/B0...0?ie=UTF8&th=1
AC-DC amp clamp.JPG
Location: Olathe, KS
Posts: 1,680
My VIN: 11596
Oh nice, thanks for the heads up! It's on the Christmas list :-)Originally Posted by DMC-Ron
Andy Lien
VIN 11596 Jan 1982 build - owned since Nov. 2000!
Total frame-off restoration completed 2021-2023
Photography and Backpacking is life.
Was Fargo, ND
Now Kansas City
Location: Las Vegas, NV
Posts: 128
My VIN: Jan '82 #11153
I went out and bought the UNI-T UT210E multimeter.
Zeroed the unit and clipped it on the positive cable wire near the battery. With only the passenger door open on the 2A scale it read 1.105. With the door closed it read 0.042. Pulling each fuse, the only change was with fuse #11. It then read 0.011 (I believe this is the radio clock disconnected) (Note: I have all the original equipment, no adds). Therefore, I see that something is drawing 0.011 amps? What else is there to check? Do I need to place the meter with the probes to each fuse position for a more accurate reading?
On another note: I disconnected the battery after it was fully charged. With that in mind I, when reconnected it started right up after sitting for over a week. I think the issues with starting has been a weak battery? Is there something in the fuel injection system that is that sensitive to voltage/amps?
Location: Leonardtown, MD
Posts: 9,008
My VIN: 03572
A stock door lock unit will draw about 0.012 amps standby. The stock console clock about 0.005 ma. A radio clock another small load. So your 0.042 standby is not that bad.
It takes a long drive to charge up a low battery fully. So many short drives will not do it. You may just need to charge it once a month or use a battery tender.
By the way, I ordered one of those meters because it has such a good low scale reading for a clamp on unit.
Last edited by Bitsyncmaster; 12-05-2022 at 03:16 PM.
Location: Las Vegas, NV
Posts: 128
My VIN: Jan '82 #11153
So, you don't think this amp load as measured above would drain the brand-new battery in 2 days? That's my thoughts but it did happen. I wouldn't think the battery is somehow bad? I keep thinking back to the issue I have with the dome lights - the low (4) volt on the one, 12 on the other.
Oh well, always something with this car. I'm told that's the fun of own it.
Location: Leonardtown, MD
Posts: 9,008
My VIN: 03572
No that small drain would not kill it in two days. You must have an intermittent larger drain sometimes. Do your dome lights go on when the doors are open? Next time you stop it overnight, look to see that the dome lights are off. I remember another owner had a bad radio draining 0.2 amps but that was constant. Can't think of much else that would be an intermittent load.
You can pull fuse #12 which should kill the door, dome, glove box, trunk and engine bay lights.
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Dave M vin 03572