1996 SL600 Terminal X4/10 Connectors 61e and 87L
 

The attached photo shows the terminal block X4/10 located behind the passenger side airbag on my 1996 SL600. I am having difficulty understanding the functions of terminals 61e and 87L.

What I really need to know is when should these terminals be hot and how do they get there power. Looking at the wiring diagrams:

The 61e terminal is connected to the following:

Airbag Module N53
ADS Module N51
Exterior Lamp Failure Monitor N7
Instrument Cluster A1
ESP Module N47-5


The 87L terminal is connected to the following:

Basic Module N/16
ADS Module N51
Transmission Control Module N15/1
Shifter S16/9
Instrument Cluster (Check Engine) A1
Steering Angle Sensor N49
Level Adjust Switch S77/1

One of these modules must be providing power under the right conditions:

Anyone ????

John, I don't have SL schematic, only have W140. But I believe terminal block X4/10 is the source of all positives. The battery and alternator positives are connected there as well as all unfused power consumers. In W140 battery positive has 2 wires one 10sq. mm and the other 70 sq. mm. The first one comes to X4/10 terminal one and feeds some of the modules and the fuse box. The other big 70 mm wire from the battery goes to X4/10 terminals 2, 3, and 4, all connected together. It feeds the starter. Alternator wire also connected to 2, 3, 4.
So the X4/10 is battery/alternator positive. All wires there have power at all time and unfused.
Reg. Mike

On the 129 diagrams the X4/10 terminal block is shown as a 6 pin block. In reality the block is divided into one 2 pin and one 4 pin blocks. What I am showing in that picture is the second block with pins 3, 4, 5, and 6. The first block with pins 1 and 2 is where the 70mm cable and alternator attaches and pases through the fire wall. Pin # 3 was not used in my car and pin #4 is conneceted to pins 1 and 2 as you say, hot at all times.

It's pins 5 and 6 I'm concerned with these are the labled 61e and 87L respectively. I do not believe these are hot at all times.

Circuit 61 refers to the "exciter" signal to the alternator.
On that & most MB's upto 2000 was done by the cluster.

All circuits marked "87" are switched circuits, most by some form of a relay.

On your car when the ignition is on the Base module powers circuit 87L.

61 and 61e are different.

On my wiring diagrams the alternator light is on circuit 61. The alternator is not on the circuit 61e wiring diagram at all. It does appear that the circuit 61e terminal must act like the circuit 61 alternator terminal however I cant figure out how power gets from 61 to 61e.

That was my guess. but guesses could be very expensive in this area.

Thanks.

Thank you M.B. DOC and Bobterry99.

Based on that info I will proceed with the assumptions using a test light first. That 61e is getting fed through the instrument cluster via pin 4. I will also disconnect the BAS module wire and test it for output. This should safely confirm everything.