Parasitic draw problem

[HDdave]

Hey everyone, Still in the process of trying to save this e90 I picked up on the cheap.. I will say this car is substantially more challenging than my e46. Still fighting some codes I think I will have to go under the valve covers for (strange vanos max position code) Which according to ISTA the last step to fix that code if camshafts are timed correctly is replace DME. Which honestly has me wondering if all my fault issues are electronic.


I am finding out that I bought myself someone elses electrical nightmare. I thought it was just an old battery not holing charge at first, but that was not the case at all. Now in doing some more digging I have found MULTIPLE fuses missing, and what looks like someone cut off, then but connected on a new connector for the blower motor. I attached some pics..

Right now I am at .98amp draw (using ANCOR amp clamp). I have tested alternator diode already, and in the process of workign my way through the fuse box one at a time (also restoring it to have all of the fuses it should have from factory)

I did notice a drop down to .46 when I removed the large square black relay on the right side of the fuse box (it was also pretty damn warm). So I plugged that relay back in, then amp draw jumped up to 6 or so (same as when opening the door) and it settled back to .98 (in that general area). So I then unplugged the group of wires in the top left.. Same exact drop as when I removed the relay.. Continue on- fuse 36 causes exact same drop, and then jump and re settle to .98. I tried removing all of those at the same time- nothing different, still at .46..


This ISTA screen shot is after clearing codes to get rid of the engine codes (theres also a weird throttle actuator line code- not the normal actuator codes). I did not start the car after clearing and before taking this read out. This shot is before restoring the fuse box to factory according to the card in the glovebox. There is a code in here for drivers seat no communication but that is solely because i had taken that fuse out and put it back into the pass side not knowing. Let me know your thoughts..

[HDdave]

There is also this read out from before I cleared it, most of that is just from stuff being unplugged. But I wanted to post this anyways as well

[RocketyMan]

So keep in mind that modules are "awake" whenever you open a door, touch a door handle, EVAP system checks, etc. You need to wait for all the modules to go to "sleep" to get a true value of any parasitic draw. There are some things that happen in the background of the car that can take quite a while to perform before eventually all going to sleep.

It might be worthy to invest into a FLIR camera and point it towards the JBE to get a better understanding of what circuits are continually drawing. To do this, you'd need a cold car, and usually leave a door open with the JBE fuses exposed. Point FLIR camera at said fuses and look at which ones are warm signifying a draw.

[RocketyMan]

P.S. +1 to using ISTA

Once you figure out which fuse is causing the parasitic draw, you can then use ISTA to look at the circuit diagrams to figure out what suspect module or "thing" is causing the draw.

[HDdave]

Okay, my buddy does marine electronics so honestly he might have access to a flir camera. But the large black relay on the right side of the fuse panel was noticeably warm to the touch the other day when I was investigating, the draw also dropped almost in half when removing this. I have been letting the car settle after opening or closing a door.

Right now I am going to put the whole fuse box back together the way the factory intended.. Hopefully to get some what of a better base line. I might even go take the car for a test drive just for the hell of it to see how it acts..

I have a feeling this is going to be quite difficult to nail down.

[askjeeves]

Do you ever hear clicking coming from that relay? Or notice your lights don’t turn off when you turn off the car? If so, look up CAS module issues.

[F4rmost]

Originally Posted by HDdave

Now in doing some more digging I have found MULTIPLE fuses missing, and what looks like someone cut off, then but connected on a new connector for the blower motor. I attached some pics..

I don't have much input on all the other things, but there is a recall on these cars to get the blower motor wiring replaced. This may be a factory recall being completed.

[RocketyMan]

Originally Posted by F4rmost

I don't have much input on all the other things, but there is a recall on these cars to get the blower motor wiring replaced. This may be a factory recall being completed.

Great point. I question if that was the correct way to do it. Maybe it is--it just looks janky which I think the OP is/was concerned with.

[HDdave]

Originally Posted by F4rmost

I don't have much input on all the other things, but there is a recall on these cars to get the blower motor wiring replaced. This may be a factory recall being completed.

This does make me feel a little better.. It does look a little sketchy but is properly done and sealed very well. So that would make sense.

Now here is the interesting part that doesnt make total sense- but kind of does. The fuse box and pulling them one at a time was starting to piss me off to be honest. And once I realized half the fuses in there were the wrong amperages, I just decided to gut the entire JBE of every fuse and relay. I then went directly off the card in the glovebox (thankfully it was there still) and reinstalled them (probably should have changed them all for new in retrospect) but filled in with new ones, all in the correct amps.

I now have 0.0-0.1 draw.. Will this last? Beats me but I am going to button up the underside and take this thing for its first test drive since I bought it in the beginning of May for $15k. Did the clutch, flywheel, driveshaft, guibo, needed a new rear end as well.. So wish me luck..

[HDdave]

In an update.. I didnt get a chance to take it for a test ride bc of some suspension adjustments I needed to make and now I am too tired to put the plenum back on.


But now- None of my door locks work, nor does my trunk latch. So yeah who knows

[RocketyMan]

Originally Posted by HDdave

In an update.. I didnt get a chance to take it for a test ride bc of some suspension adjustments I needed to make and now I am too tired to put the plenum back on.


But now- None of my door locks work, nor does my trunk latch. So yeah who knows

Okay. Do you have comfort access? Is that what you're referring to not working? Also, the CAS may need to initialize these things in order to get them to work again.

As an FYI, there is a slight chance the FRM could be damaged in some crazy events. But the JBE controls all the motor functions for these things. The CAS controls the request for these things, like rear trunk switch and interior switches. The FRM has the door latches.

[HDdave]

I should have been more specific, yes I was referring to comfort access, but also the door locks will not operate with the button on the dashboard either.

I was able to take the car for a nice hour long drive around town last night. Engine ran surprisingly well, although right upon starting/ first couple lights you come to it would want to stall out. Then I would have to feather the throttle to get it to crank back up.. No CEL came back on though, or any reduced power. It did however feel like it was lacking throttle response. Maybe I am just used to my much louder and tuned e46.. But something just didnt feel quite right.

Here are some things that didnt work, which did work before I emptied and redid the fuse box based off the card in the glove box. Fuel Gauge (it thinks its empty), comfort access (key has to be in the ignition to start car- keyfob does nothing), rear windows, trunk latch, right rear turn signal (I need to check this bulb because I had got it working when I initially got the car- thinking there may be something surging and blowing the bulb), door lock button on dash, Air conditioning (blower comes on, so does climate control, but AC condenser does not- and I definitely felt it blow ice cold when I was diagnosing things right after I first bought it)

By the time I finished I did not do an ISTA read out. Hopefully that was not a mistake because I did unhook the battery overnight (my line of thought was I dont want it burning my house down haha). Also when I went to unhook the battery I noticed the small black fan (which sits behind whatever module is on the left center trunk floor) was still on one hour after the car had been parked..

I have been doing my own research, but also working through the whole process with chat gpt. I have never attempted to fix a car with a supercomputer search engine but it been helpful of keeping my thoughts on track at least. Its telling me that just because the diagram in the fuse box shows all of the fuses, and their amperages does not mean that all those should be filled... Which I suppose makes sense I mean GM products leave a bunch of empty spaces. But I honestly thought the Germans would put a card in there that matches your actual vehicle. Whats yalls thoughts on this?

[RocketyMan]

That's the satellite fan. It's supposed to cool the telematics module, or at least flow air around in there since it gets warm.

[HDdave]

Im starting to wonder what all I could possibly delete and code out the errors.. I put an Andream carplay screen in it. Dont need satillite radio or anything like that.

This car also does have individual audio- not sure if that bit of info helps.

Here is a question then- What source could I turn to, to find what fuses actually should be installed in this car based off its options.

[GORDON.M3]

Originally Posted by HDdave

Im starting to wonder what all I could possibly delete and code out the errors.. I put an Andream carplay screen in it. Dont need satillite radio or anything like that.

This car also does have individual audio- not sure if that bit of info helps.

Here is a question then- What source could I turn to, to find what fuses actually should be installed in this car based off its options.

im pretty sure its its the andream. that photo you took of the red wires that have been tampered with is if I'm not mistaken the blower wire/motor recall.