S320 electrical problems

You need a skilled auto-electrician, not a mechanic, one that has a high end scan tool computer that can analyze the stored and live data, plus reading any DTC Codes.

To me, it sound like you have a failing battery, possibly erratic charging and some bad grounds. The electronics on Mercedes are overly complex.

I got this free Pdf manual from reliable-store for free and I don't think Ive visited a mechanic or fixya for help for more than 3-4 times out of the 20 times I fixed the chipper in these 4 years

Does the vehicle have electric trailer braking ability? IF it does then you may have tapped that instead of the brake lights. If it does not we need the make model and year of the vehicle.

their are some electrical issues with s320 throttle valve electric failure --coil pack failure -- check fuses and relays then check battery and connections and try to start with boost if starts check and test battery and alternator --and check the wiring connections for loose , frayed , damaged ,and corrosion the following link are some of the problems acossiated with your vehicle
Newest Problem Reports for the 1999 Mercedes Benz S320

is not engaging or have an electrical problem with system

may have left a ground wire off behind the dash or the main connector isnt seated all the way in..

my QUESTION is: where IS the "top ajar" light on my 2007 VW New Beetle convertible??

Diodes are part of the electrical system that allow for electricty to flow in only one direction. They are used to help protect the computer systems in your vehicle. How fast are you going when you shift into 4-wheel drive?

2001 Mitsubishi MONTERO 01 - Transfer Case > POWER TRAIN : TRANSFER CASE (4-WHEEL DRIVE) [Part 104000 ]
TSB No: 0223007 NHTSA ID: , November 01, 2002 : Replacement:
Summary: 4wd indicator lamp flashing / diagnostic trouble code (dtc) 33.

2001-02 Montero
A flashing 4WD indicator lamp and/or DTC 33 may be caused by corroded transfer case shift position switches. The original switches are susceptible to water damage, and new revised switches are available to prevent the problem.

PROCEDURE

1. Replace the five transfer switches

2. Clear the DTC, using the scan tool.

3. Test drive the vehicle to confirm the 4WD indicator lamp does not flash and DTC 33 does not reset.

could be numerous problems, but you are correct in assuming low freon...try that after visual check under hood confirms no obvious failures like missing drive belt or disconnected electric wires...