SharkSkin

Of course you're welcome, Bill -- though Sunnyvale might be a bit of a hike.

Bill Ball

I hike almost that far every day - Milpitas.

SharkSkin

Awesome! Will definitely keep you posted! I know you've told me that before but it just didn't sink in.

SharkSkin

Guys, it looks like Wednesday or Friday right after work I could squeeze in a couple hours. Does either day work for you guys? If not maybe Sat. or Sun. after the drive?

Bill Ball

Dave, all are possibilities.

SharkSkin

Cool, let's find out how Constantine is doing.

SharkSkin

Well, Konstantin, Bill & I all did some head-scratching on this, and it seems as though the problem is in the wiring somewhere. We're going to try and get together again on it this weekend if we can. We have a 100mA drain and a 170mA drain still unaccounted for. The 170mA is on one of the smaller wires that connects at the battery that feeds the brains & interior lights, though we ruled out both of those circuits(I think? ) by pulling fuses and relays. There is also a 100Ma drain that seems to be related to a clicking noise under the driver seat, which disappears if battery power is interrupted, but reappears if we connect the battery, turn the ignition on & off, then lock. I think I have all that right, please correct me if I'm wrong, guys.

Nicole

I wonder how much the flashing LEDs in the door locks would draw... Also, the newer models leave the digital display light on for a few minutes after you shut off the engine - this way one can read the mileage for a short time, even with the key removed. And then there are all these relays/electronics that delay the shutoff of interior lights, etc.

Of course I have no clue what I'm talking about, so take this for its entertainment value!

SharkSkin

Yes, we found that the digital display went out after a few minutes, or upon locking/unlocking the doors. we ruled out the LEDs and alarm by checking with doors unlocked/alarm off. I suspected that one of the electronic timers in one of the relays had frapped out, but we pulled all of the relays with such features and still had the same problem. Now that I'm thinking of it though, I think the fog light relay has a couple diodes in it... one could be shorted. I'll have to look at the diagram.

Anyway, thanks for the entertainment -- good ideas actually.

Bill Ball

It was confusing. I think what we were left with is:

50 mA draw if you pull the power window fuse and pull the battery ground temporarily and reattach it. That is normal draw.

~150 mA draw if you just pull the power window fuse but do NOT pull the battery ground and reattach. So, there is SOMETHING that is drawing 100 mA that drops if power is interrupted. You suspected a relay that is latching but not releasing. We pulled almost all relays with no change, only not pulling the 53s. ANYONE HAVE ANY IDEAS ON THAT ONE?

~350 mA if you don't pull anything. So, the power window circuit is contributing 200 mA parasitic draw. We did not get to diagnose that further. It was the power window relay that was clicking under the seat every time we attached the battery ground. It did not click if we pulled the power window fuse., So, it is possible that relay is misbehaving. We did not get a chance to dig under the seat for that.

So, in summary 100 mA mystery draw that disappears if ground is broken and 200 mA power window draw. Both need further investigation. But I am convinced we have nailed the draw levels. Before I got real confused by changing draws, and that was resolved when you noticed that the draw dropped 100 mA after a temporary power disconnect.

More fun is planned for Sunday.

Luis A.

I likely get the prize for resurrecting a 15 YO thread...

'88 S4. Rear AC.

I have a similar 90-100 mA current draw with all doors closed. I removed all relays, two at a time, and saw no change. Removed all fuses, 5 at a time and saw no change.

If I remove the two ring terminals (one has two red wires, the other, one wire) that attach to the large red wire ring terminal nestled in the jump start pole phenolic holder, and then reconnect them, the draw is gone once.

Any ideas? My next step will be to play with the alternator connections. Anything else to eliminate prior to lifting the car and hunting for the alternator..?

TIA, Luis

Luis A.

I’ll add to my observations above that after the cars sits for maybe about an hour, the drain drops down to 12 mA.

So while it appears I don’t have a chronic high current drain I wonder what sits there for about an hour consuming ~90 mA and then shuts off…

Alan

Pull the cooling fan controller - silver box under the passenger sill cover (under the panel with the hatch release pull). The cooling fans won't run without it! But see if it solves your issue. The controller is designed to stay active after the car shuts down - but not for that long.
Do your interior lights work in door switched mode? 12mA is good, so whilst the timing seems off - this 100mA for an hour will not cause any problems.

Alan

worf928

Are there any references (besides the troubleshooting tree in the WSM) that will make that black box a little more transparent?

Alan

Dave - not that I know of - but its the brains of the whole cooling fan/flap system - the final stage is just the motor drivers and fan failure adaptation. All the control logic is in the controller that monitors all the sensors and system state. These include water temp, intake over-temp, torque converter oil temp and AC high pressure. This module is powered by Battery (30) (NB unfused) and also Ignition (15) (fused - usually via X-Bus), it also monitors hood open/close status and AC on/off status. After ignition off the system stays active for the 'Fan After Running' mode: Fans run after shutdown if the intake is very hot (=> whole engine is very hot) until the intake temp is sufficiently cooled (via Intake Temp Switch). This function employs a timer after the ignition is turned off. I'm not certain of the timer length - but functionally even 5 minutes should be plenty adequate to cool the engine. In many locations this would never be triggered. In Phoenix in summer-time its a daily thing - but even here I don't think my fans have ever After Run for more than 2 minutes max - usually 20-30 seconds - just as well for the battery. Note the fans will only After Run if the hood is closed (to keep your digits intact)

In my experience these controllers are pretty reliable (they live a pretty easy life) - so likely used replacements are also very viable for long term use and likely quite plentiful from a supply/demand basis

Alan