Engine bay + terminal
 

Has anyone used the engine bay terminal for parasitic battery drain testing? I'm curious if a clamp meter would work there? I'm interested in using it for testing fuses under the glove box. The rear fuses I can test with the spare wheel out. Basically, a one person test without having to walk around to check the amp meter. Since I have a Foxwell, I can command sleep mode. Whatever is keeping it awake, will come back on. The inside motion sensor is unplugged for now. Two things will be checked quickly. The light control module and rear upper hatch wiring.

I think you need a battery to determine draw from a unintended source since the meter needs to between the battery and the positive cable not at the termination end of that cable

Correct. That terminal will disconnect the alternator and starter from the battery. Unfortunately not helpful for your desire.

Ok, thanks. The alternator is new. I've seen eyeing the starter for replacement. it has no problems turning over the 3.0. It spins hard and strong a good charged battery. Age is my concern. I'll be curious to put the clamp meter at both locations to check for a difference.

Difference in what ??

Engine bay + terminal
 

The starter current goes through one cable the current will be the same no matter where you measure it


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I had a chance to check amp draw today. It’s pulling 0.67 milliamps. I tested the rear fuses. Only 72 and 75 indicated voltage drop. Pulled both of them. No change. The rear hatch and door were latched closed. The Foxwell was used to command sleep mode. It woke up after a second. The door window switch light came back on. The radio can be turned on without a key. So it’s a confirmation it’s awake. Next, test all the front fuses for voltage drop.

Bluetooth multimeters are pretty handy for this. You can get an amp clamp with bluetooth for ~$50 on Amazon

Do you mean 0.67 amps (670 milliamps)? 0.67 miliamps is a tiny current and the X5 battery would last months if not years with this load... :dunno:

It's 0.67 milliamps if the door switch window light button is off. I've kept it off so it would drain less. On a full charge, it takes two days before it won't crank up anymore. As soon as it's warm, I'll do a full 16 min amp draw test. I won't use my Foxwell command for sleep. I put the clamp meter on the positive side. It read up to 1.5 amps. The readings were not accurate. The clamp was used by clamping on both positive cables or individually. Once I moved the clamp to the negative side, 0.67 is the lowest I saw.

It's 0.67 Amps, not 0.67 mA that you are reading.

You should read the same value (within experimental error) on both the positive and negative cables to the battery. If you are not able to get that, I would get that issue solved before worrying about what the numbers are telling you. Otherwise, you might be chasing theories based on wrong info.

With a 3.0i, the only way measuring up by the engine bay terminal would be helpful is if there is a short in the alternator or starter. Possible - and it does happen (often the very last place someone would think to look when tracing a parasitic drain), but I expect if they exist they'd be higher than the 0.67 A. For the 3.0i (different in this regard vs. the V8s or diesels), the jump port in the engine bay comes from the battery, goes to the starter (where the engine block is used for the ground), and then continues to the alternator, where the cable ends (and the engine block is used for ground).

Cool test you can do with your clamp meter up in the engine bay (for 3.0i) - clamp on the cable coming out of the jump port (going to the starter) and start the car. It should immediately jump to a couple hundred Amps (the starter draw) while the starter spins, then immediately following that, it will probably swing to about 80 A negative as the alternator replenishes the charge the battery just used up. That 80 A should then drop to around 20-30 Amps over the next few seconds as the charge used in starting is restored and the alternator just needs to power the car as it runs.

I would not suspect a bad starter just based only on age. When I had my engine apart a few years ago, I took the starter apart to refurbish it. 186k miles and 17 years old. I replaced the brushes, etc., and they had about 70% of their life left. But my experience on starters in all my cars is that they last forever until you have a problem where the engine won't start (fuel issue, etc.), and then while figuring out that problem, the starter will burn out from all the failed start attempts that cook the windings, brushes, etc.

12V troubleshooting is easy for me. I've learned. Chasing amps is new. I'm learning as I go through the X5's complex electrical system. Here's a snap shot with both + battery terminals. I can't remember if this was before or after removing the Foxwell scanner (used for sleep command).
0.84-0.92 readings.

:thumbup:

One trick with the clamp meters is to zero them while in the vicinity of the wire(s) (orientation and location as close as you can get it). They work by measuring the magnetic field created by flowing charge, and ambient field can produce a non-zero reading even with no wires enclosed within the clamp.

You should be able to measure both wires at the same time as you show there, or one at a time, and add them - and get the same result either way. And as said before, the negative cable should show the same number (the battery does not actually store electrons, it stores the energy chemically).

Main thing is to get things figured out so you have reliable numbers to work with.

Thanks oldskewel! I'm learning. If I remember correctly, the Foxwell was still connected at the time. Readings dropped after I took it off. Readings did change depending on which direction I held the meter. I didn't compare both +/- sides afterwards. I'll run more tests later this week.