Fuse #6 Blows When In 'B' Gear - PeachParts Mercedes-Benz Forum

MB-Dude · #1 07-31-2007, 10:45 AM

Need help in troubleshooting as I do not have access to detailed wiring diagrams. In my ’94 SL500 with an automatic transmission, whenever I move the shifter to ‘B’ (1st gear), fuse #6 blows within a couple seconds. If it is very quiet, such as in the garage, I can faintly hear a whining noise from the engine compartment from the moment I shift to ‘B’ and when fuse #6 blows. This problem is very repeatable and happens whenever the shifter is moved to position ‘B’. Normal driving does *not* blow fuse #6, although this vintage begins accelerating in 2nd gear from a dead stop - normal operation.

According to the Fuse Designation Card in the main fuse box, fuse #6 protects “Relay Left Safety Package, Backup Lamp, Horn, Power Soft Top Control Unit (Fanfare Horns, Outside Temperature Gauge)”. These items all seem to work individually, without fuse issues. However, when fuse #6 blows, the power windows stop working (?) and there is a steady, repeating 'beep-beep-beep' that is heard from around the passenger foot well.

I believe the problem (a short or defective component) is somewhere in the electrical circuit between the ‘B’ Gear Switch (located directly under the shifter gate and activated by the shifter) and the transmission. Somehow, this electrical circuit is tied into fuse #6.

Strife · #2 08-01-2007, 12:05 AM

Weird, but true: I discovered this problem on my 86 560SL soon after I bought it. Cause: Kickdown switch wire to the transmission solenoid trapped between the transmission pan and body of the transmission, cutting through the insulation and grounding the wire to the transmission. Last service at: MB dealer. Your car might be wired differently but this still might be worth a look.

MB-Dude · #3 08-01-2007, 09:26 AM

Thanks Strife for the suggestion. Will check it out. The problem is definitely something having to do with the 1st gear electrical circuit.