Voltage drop difference w/ Injector relay removed?

[kimiraikkonen]

So I've been chasing some electrical gremlins. Tell tale sign is the "clicking sound" from the glove box when moved to the ignition 2 position and intermittent no crank situation.

To baseline, I have:
1) changed/registered a new AGM battery
2) cleaned up the fuse box and fuses
3) engine ground cable was replaced
4) checked battery terminals to make sure clamped down to torque specs

Since then, the starting situation has improved dramatically. I don't drive the car often, but I would say 1 out of 40 starts, it will momentarily not click and then the next time fire up right away. The multiple "click" sounds from the glovebox have gone from multiple 5-6 clicks to just a single click now when turning on the car.

What I do notice is that even when charging up the battery to a full 12.6V with the CTEK, the car will level set in a few days to the 12.25 to 12.35V range. I ran drain tests in ISTA and it showed no excessive current drain issues with the modules.

- Voltage measured at the terminals in the engine bay match the voltages at the battery terminals
- If I disconnect the starter line at the engine bay and measure at the engine bay terminals, I see the same voltage, so this shows there's no excessive voltage drop because of the starter line

What I did today was open up the DME box and removed the DME relay (salmon) and measured the voltage.
- It was 12.25V, which matched the engine bay terminals reading

I then removed the beige color relay (which I think is the Injector relay) and the voltage measured all of a sudden back to 12.55 V. I put back the relays and measured at the engine bay terminals and it was still 12.55V.

I then buttoned up everything and decided to pull on the high beam stalk (car off) to see if that changed anything.
- Low and behold, the voltage reading at the terminals dropped back to the 12.25V.

Is this normal and is there some slow passive drain occuring at one of my modules (despite not showing up in ISTA).....and/or is this a static voltage drop issue that could impact cranking voltage?

Any pointers would be appreciated.

[kimiraikkonen]

I was diagnosing the car yesterday with ISTA, with ignition on Kl15, and noticed the battery voltage dropped pretty quickly with it on, ~20-30 min. Voltage had dropped down to 11.9V despite it being plugged into a CTEK at the same time.

Is there some draw happening in the ignition circuit?

[kimiraikkonen]

Fully charged battery up with the CTEK 4.3. Next morning, with the charger still plugged in and the car in position 1 ignition (KL-R position):

- Measured 12.5V at trunk battery terminals
- Measured 12.49-12.50V at the engine bay battery terminals
- Measured 12.49-12.50V at Fuse 12 in the fuse box

Secret BMW dash menu shows voltage at 12.3V??!?!?

I'm thinking of an internal relay issue in the CAS, does this jive with what I'm seeing?