Measuring Parasitic Drain with an AMP Clamp

Parasitic drain or draw is a common concern on vehicles that can discharge the 12 volt battery while the car is sitting. This can create big issue and even leave you, or your customer stranded. Measuring parasitic draw properly and efficiently is an important repair procedure. In this video, we talk about what parasitic draw is and how it is measured using an amp clamp. I chose a PDI amp clamp that requires a meter for this video, but there are MANY options out there. At the end of the video, I discuss some common specifications for draw measurements, the importance of waiting for the modules to de-power, and what next steps would look like for a excessive parasitic draw measurement.
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Components in the video:
- BluePoint MTIND683A ( shop.snapon.com )
- PDI (Now TECPEL) CA-60 Amp Clamp ( amzn.to/3yGIZko )
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[@nickayivor8432]

Adams 's Analysis Tutorial great 👍 👌 From Nick Ayivor from London England UK 🇬🇧

[@AdamsAnalysis]

Thanks for watching!

[@davidm3210]

Very nice tutorial, thank you.

[@le3aerialphotography870]

Thorough explanation. Thanks!

[@AdamsAnalysis]

Glad it was helpful!

[@Lambros_Stefaneas]

Nice and information video.

[@andrewlewton1331]

Very good explanation, slightly more complicated by the equipment you were using, rather than a clamp with a built in screen. But not a problem if you listen carefully and are serious about doing the job properly. The alternator diodes were interesting, could you identify them by this method?

[@AdamsAnalysis]

Thanks for watching! Yes, when I've suspected an alternator causing a drain, I take the clamp and go around the alternator output wire while minding the polarity of the current. This can quickly show if the alternator is consuming energy in its resting state.

[@TheFuneralDirector]

Great explanation ....subscribed , stay safe Regards Andy

[@AdamsAnalysis]

Thanks, you too!

[@stanjong2727]

Great video , very descriptive and I learned more about what/ what not to do! I don’t have much experience diagnosing problems that have a parasitic drain but I have experience with electrical/hydraulic diagnostics.

[@AdamsAnalysis]

Glad it was helpful!

[@deankoehn7869]

​@@AdamsAnalysis 7days. Rxc v

[@thepiecesfit5049]

According to my amp clamp manual when you zero out the clamp reading you need to hold your clamp in the same orientation as when performing the reading, otherwise the reading will not be accurate.

[@cujo7240]

Where do you find out what the normal parasitic amp draw value is for a given vehicle while the vehicle has entered sleep status?

[@NEMOJA]

50ma is specs on every vehicle 0.050A

[@barrieoleary2719]

Amp clap drain test setting

[@robertmccully2792]

Where do you find the amp draw in the manual spec, when car is at sleep? I can not find it?

[@AdamsAnalysis]

Parasitic draw specifications can be difficult to find in a service manual at times. It is something you will not find in the owner's manual. Most vehicles pre-2000 should be less than 25-30 mA depending on their configuration of electronics. A newer vehicle with many electronics can see a draw spec of up to 80 mA.

[@randy1ization]

why would my dc ampclamp show a 11 milivolt draw on the negative cable and a 54 miliamp draw on the positive cable?

[@tulta3631]

I'm not entirely sure I'm correct but I'll give it a shot: The difference comes from the batteries' capacity. The extra capacity of the battery weakens the necessity to pull the extra 40mA from the negative, rather from the acid cells in the batt. the mA draw is too weak to pull it from GND cable in other words.

[@AdamsAnalysis]

This is a good speculation. I would first ask about setup and whether you are truly capturing all ground paths to the battery. The next question would be the possibility of interference. Amp clamps are unfortunately very vulnerable to influence. When a difficult drain is being assessed, it may be better to put a meter in series and eliminate some of these variables.

[@rentoiee]

😴💤