1985 300TD Wagon

I picked up a new fully-charged battery at NapaAuto last night, put it in, car starts beautifully. No starter/ignition issues. I tested all the fuse terminals. Fuse terminal #2 is drawing a few amps (around 2 - 3).

Also, fuse #10 (for the rear defroster) is drawing a few (1.4) mA (mili-amps) (I don't think this would cause a drain, but you guys would know better than me).

So fuse #2 - it is for the following things:

- clock
- trunk light
- diagnostic (?)
- switch-over valve seat back arrester (?)
- front & rear interior roof lights
- hazard warning system
- antenna
- illuminated vanity mirrors
- warning monitor term. 5 (electronic radio)

What is "diagnostic" mean? And is the switch-over valve seat back arrester for the sedan models where the rear headrests would come down via a switch?

Also, how do I start diagnosing to find which one is the problem? I removed the roof light bulbs and tested again to see if that was the issue. It didn't. Would removing them stop the draw?

Here's another kicker: When the driver's door is open, the terminal draws way more amps than if the door is closed (around 4 I think). This leads me to believe that it may be the interior lighting, but how can I test this?

For now, I'll leave the fuse out. I don't need the trunk light or interior lighting, clock, etc.
But do I need the "diagnostic" to work? What the hell is this referring to???

 

Remove the Light Bulb from the interior Light. Open the door and see if it still draws those amps. If it does that could be a short in the wiring of the switch that activates the interior lights.
While those amps are drawing with the door open try pulling the Power Window Fuses. If that stops the amp draw you have a short in one of the wires going to the Power Window.
Try giggeling the Ignition Key around a little and see if that makes any change. If it does it could be the Ignition Switch is going bad.

 

You make no mention of why a new battery was necessary. I just went through a similar experience. For about a week, my car was displaying some odd characteristics. I have a 96 E300D, and when I would start it, the red and green lights on my rear view mirror would blink on and off, and my instruments acted erratically, with the needles moving up and down. I have a Scanguage attached to my car which shows the actual voltage when the car is running. Well, while running, the voltage dropped to about 11.5 volts, and stayed there. Managed to get the car home, parked it overnight, and in the morning the battery was totally dead. Took the battery out, recharged it, and it seemed fine. Put it back in the car, and in a matter of 10 hours, it was dead again. One of the posters on another forum had mentioned the fact that sometimes, a diode in the alternator can short out, and ground the case to the engine block. I decided to check that out first, and sure enough, with the engine off, there was a current drain from the battery cable to the alternator post. All you have to do to check this is with the ignition off, disconnect the battery cable from the alternator post, and see if you get a spark. If you do, that is your problem. If not, then further investigation will be necessary. Hope yours is an easy fix.

 

If you have a clock in the car, you will get a spark.

 

You should have no spark at the alternator battery post with the engine off. If you do have a spark at that location with the ignition off, your alternator is feeding current to the engine block via its case.

 

His Car is a Diesel and it has an Electrical Connector with 3 slots.
The 2 large slots connect to 2 fat Red wires and have Battery Voltage all of the time.
The single small Slot has a skinny Blue Wire that goes to that goes to the Low Charging Warning light.
With the Ignition Key off there is no voltage to the Blue Wire. With the key on you get voltage.
If the Low Charging Warning Light Bulb is burnt out your Alternator will not charge as it needs the resistance of that Bulb to get your charging going.

In unplugging the Electrical Connector I do not think he could see a Spark as the connector sinks into the Alternator Housing about 1/4 of an inch.

 

Thanks for all your input.

I have removed all of accessories on the #2 Fuse and guess what happened. NOTHING

I still have 3.5+ amp draw on the battery. I am not sure where the draw comes from and with the car not running how could the alternator cause the draw unless the voltage is going through a bad diode. I am confused.
I can only assume there is another component (like a relay) stuck. Hmmmmmm.

I have spent two whole days gutting and reassembling every electrical component connected to this fuse. Probably a good thing as I found a few bulbs out and replaced them. Other than that I am stuck in a rut.

Any help will be most welcomed.