Is a 5.0A Parasitic Draw a lot?

S

StylingSequ

2023 Mazda CX-5
≈14 months old

In a previous thread, I mentioned that my car's battery kept dying. I've been going back and forth between the dealership and the body shop that did some front-end work about 4 months ago. I thought that it might be the battery, but I was able to do a parasitic draw test. It came out that 5.00A is trickling while I have everything turned off.

I haven't started pulling fuses to isolate the problem because I accidentally touched the negative and positive terminals together while in ammeter mode. Now, my multimeter has shorted out, so I'll have to go buy another.

In the meantime, does anyone have any idea what might be causing this in a newish CX-5?
 
5 amps is a LOT. Normal is ~50 milliamps.

The only way to find out is to test fuses. You don't need to pull them to test. In fact, it's best that you don't.
 
N7turbo said:
5 amps is a LOT. Normal is ~50 milliamps.

The only way to find out is to test fuses. You don't need to pull them to test. In fact, it's best that you don't.
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Oh, I watched a video where the guy said to pull out each fuse until the amp drops to about 50 milliamps. I'm guessing you're saying to test the amount of amps across each fuse?
 
StylingSequ said:
2023 Mazda CX-5
≈14 months old

In a previous thread, I mentioned that my car's battery kept dying. I've been going back and forth between the dealership and the body shop that did some front-end work about 4 months ago. I thought that it might be the battery, but I was able to do a parasitic draw test. It came out that 5.00A is trickling while I have everything turned off.

I haven't started pulling fuses to isolate the problem because I accidentally touched the negative and positive terminals together while in ammeter mode. Now, my multimeter has shorted out, so I'll have to go buy another.

In the meantime, does anyone have any idea what might be causing this in a newish CX-5?
Click to expand...
Yes, 5 amp is a lot. A very popular YouTuber with YouTube channel called "Car Care Nut" recently posted a video on troubleshooting a parasitic electrical draw. To give you an idea of how much electrical draw to expect, turning all inside lights drew about 0.7 amp. Turning the headlights drew 3 amp. The root cause of high parasitic electrical draw could be a short somewhere or a stuck relay. Below is the link for the video.

 
StylingSequ said:
2023 Mazda CX-5
≈14 months old

In a previous thread, I mentioned that my car's battery kept dying. I've been going back and forth between the dealership and the body shop that did some front-end work about 4 months ago. I thought that it might be the battery, but I was able to do a parasitic draw test. It came out that 5.00A is trickling while I have everything turned off.

I haven't started pulling fuses to isolate the problem because I accidentally touched the negative and positive terminals together while in ammeter mode. Now, my multimeter has shorted out, so I'll have to go buy another.

In the meantime, does anyone have any idea what might be causing this in a newish CX-5?
Click to expand...


As I asked in your other thread, how EXACTLY are you measuring the current draw of the battery?
 
PLEASE don't start multiple threads for the same thing!

As I said on your other thread:
"The circuits in the car will still run for a time after turning off the ignition. Leave your meter IN PLACE and come back after ~20mins or so, and report back the reading then."
 
RedBaron said:
PLEASE don't start multiple threads for the same thing!

As I said on your other thread:
"The circuits in the car will still run for a time after turning off the ignition. Leave your meter IN PLACE and come back after ~20mins or so, and report back the reading then."
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I started this new thread because it seemed like the problem is now a parasitic draw. I didn't want to inconvenience new readers where they have to read 3 pages of comments to figure out what's going on.

I can stick with this thread if that's what most of you guys want.

Concerning waiting 20 minutes, you're probably right. That's what might have happened before I shorted out my multimeter. Once I get a new multimeter, I'll let you know what the new reading is.
 
Conrad 16.5 said:
As I asked in your other thread, how EXACTLY are you measuring the current draw of the battery?
Click to expand...
Oops, I didn't notice your question.

I put the multimeter in ammeter mode at the 20 amp range. I think, I might be wrong, I did this. I'll have to take another reading once I get a new multimeter. (Going to pick it up in a little bit.) I'll defnitely let everyone here know what readings I get.

Although I turned off the headlights and closed all the doors, as RedBaron noted, I may have taken a reading too early. I didn't wait at all. Maybe, that's why the reading was so high.
 
stickerbush said:
On your other thread you stated that you weren't sure whether you measured 5A or 5mA.
Click to expand...

I think it was 5A but since others say this is so high, it makes me think that I accidentally put the range at mlliamps. Or maybe I simply measured the car too soon before all the electronics turned off? I'll let everyone know once I pick up a new multimeter later.
 
StylingSequ said:
Oops, I didn't notice your question.

I put the multimeter in ammeter mode at the 20 amp range. I think, I might be wrong, I did this. I'll have to take another reading once I get a new multimeter. (Going to pick it up in a little bit.) I'll defnitely let everyone here know what readings I get.

Although I turned off the headlights and closed all the doors, as RedBaron noted, I may have taken a reading too early. I didn't wait at all. Maybe, that's why the reading was so high.
Click to expand...

Man-o-man. Where's the head banging emoji?

There's two ways to measure current draw for a car battery.

1, Disconnect the negative terminal from the battery and place your ammeter/multimeter probes between the battery terminal and the ground terminal that you just removed. Place your meter in the correct mode and range and there you go. An auto ranging meter is the best but once you get the range set you're reading is right there.

2, Use a clamp on meter probe. No need to disconnect the battery at all with a clamp probe. Just clamp it on the battery terminal wire, set the range if not auto ranging and there you go.


Which method did you use?
 
Conrad 16.5 said:
Man-o-man. Where's the head banging emoji?

There's two ways to measure current draw for a car battery.

1, Disconnect the negative terminal from the battery and place your ammeter/multimeter probes between the battery terminal and the ground terminal that you just removed. Place your meter in the correct mode and range and there you go. An auto ranging meter is the best but once you get the range set you're reading is right there.

2, Use a clamp on meter probe. No need to disconnect the battery at all with a clamp probe. Just clamp it on the battery terminal wire, set the range if not auto ranging and there you go.


Which method did you use?
Click to expand...

Sorry, didn't realize that's what you were looking for.

I used the first method. I disconnected the negative and then touched the red probe to battery negative terminal and the black probe to the disconnected cable. I have a manual ranging. I'm pretty sure I set it at the 20A setting but who knows…

Since I had been checking the voltage earlier, that's why I accidentally connected the battery's positive and negative terminal with the multimeter. I saw a spark at the negative terminal so I'm guessing that's when the multimeter shorted.
 
I took my 22 turbo in for a similar 4.3 amp draw. I had suspected it was the seat heater control module, as there was a technical service bulletin that effected my vin. Dealer found rear passenger door slightly ajar, (I guess I didn’t notice the dash warning light) and the battery tested bad. There was no charge for the work.
The battery was replaced a few months before, I took it back where I bought it and they exchanged it. All is well now. Check your doors, replace battery from a known good one, then do the battery draw test would be my suggestion. It’s important to know the range, 50ma and under draw is normal for modern cars, 5 amps is definitely not.
 
StylingSequ said:
Oh, I watched a video where the guy said to pull out each fuse until the amp drops to about 50 milliamps. I'm guessing you're saying to test the amount of amps across each fuse?
Click to expand...
Pulling fuses can wake the computers and defeat your efforts to find a parasitic current draw. You need everything to stay asleep.

That means:

1. Open all doors and use a screwdriver to actuate the latches on each one. It doesn't matter if the car is told to be in "locked" or "unlocked" state.
2. Fuses can be tested using a multimeter without pulling them. You can test either for current draw or continuity.

Conrad 16.5 said:
2, Use a clamp on meter probe. No need to disconnect the battery at all with a clamp probe. Just clamp it on the battery terminal wire, set the range if not auto ranging and there you go.
Click to expand...
In my experience, trying to use the hall effect to measure DC current at very low power is unreliable because the reading is swamped by noise. The noise itself can be 50 mA or higher, and it is highly sensitive to positioning.
 
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Conrad 16.5 said:
Man-o-man. Where's the head banging emoji?

There's two ways to measure current draw for a car battery.

1, Disconnect the negative terminal from the battery and place your ammeter/multimeter probes between the battery terminal and the ground terminal that you just removed. Place your meter in the correct mode and range and there you go. An auto ranging meter is the best but once you get the range set you're reading is right there.

2, Use a clamp on meter probe. No need to disconnect the battery at all with a clamp probe. Just clamp it on the battery terminal wire, set the range if not auto ranging and there you go.


Which method did you use?
Click to expand...

As stated in the other thread, I finally got a new multimeter and measured the current. There definitely is a parasitic draw. I measured it at 4.4A. This time I left the car turned off for 30 minutes. I read that it can take up to 2 hours for everything to turn off though. I guess I'll take another reading in the morning.

It looks as if it's not the battery. Or it is also the battery since the constant parasitic draw has been draining the battery and thus damaging it. I guess this is why the battery has been dropping in voltage so quickly when things are turned on.

I'll try to measure the millivoltage across fuses to see where the draw is coming from. I'll probably do it tomorrow since it's already too dark.

Btw, is it normal that there is a spark when I touch the multimeter with the battery's negative terminal?

To test the current, I disconnected the battery's negative terminal. Then I connected the multimeter in series with the battery. I connected the black probe of the multimeter to the car's disconnected cable and then I connected the red probe to the battery's negative terminal. When I do this, there is occasionally a spark. Is this normal?
 
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StylingSequ said:
To test the current, I disconnected the battery's negative terminal. Then I connected the multimeter in series with the battery. I connected the black probe of the multimeter to the car's disconnected cable and then I connected the red probe to the battery's negative terminal. When I do this, there is occasionally a spark. Is this normal?
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A little spark is normal, but you should connect the red lead to the cable and the black lead to the negative terminal. Maybe it doesn't matter...I'm not sure. But that is how I do it.

PXL_20240820_051832648-1.webp


Caption: 11 milliamps draw on this Mercedes.
 
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The spark is normal, but you should try to avoid sparking close to the battery if possible.

Touch the probe to the battery first and try to position the negative cable as far away from the battery as possible. Batteries can produce hydrogen gas and sparks, and hydrogen, are not a good combination under the hood. Care needs to be taken.
 
N7turbo said:
Pulling fuses can wake the computers and defeat your efforts to find a parasitic current draw. You need everything to stay asleep.

That means:

1. Open all doors and use a screwdriver to actuate the latches on each one. It doesn't matter if the car is told to be in "locked" or "unlocked" state.
2. Fuses can be tested using a multimeter without pulling them. You can test either for current draw or continuity.


In my experience, trying to use the hall effect to measure DC current at very low power is unreliable because the reading is swamped by noise. The noise itself can be 50 mA or higher, and it is highly sensitive to positioning.
Click to expand...

You're absolutely right about the clamp on meters limitations. I was just stating that there are two methods for measuring current draw and I was trying to find out which the OP used.
 
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