Wiring harness, US vs Euro and emission control system

[Lars G]

During the long restoration of my 280 SL US-version -71 (built Aug -70) I have now reached the point to take care of the wiring harness. Since the harness was burnt in some areas when I bought the car will I replace it with a completely new harness.

The wiring for the light in the gear shifter are separate from the rest and same for the wiring to the heated rear window in the hardtop and are ordered separately.

During the renovation I am converting to euro style. Removing side markers and US headlights.

When ordering the new harness, I am posed for several questions.

Questions:

Is it possible to just skip and remove the emission control system and it´s harness and order a Euro harness? By ordering a Euro harness I will get the head light flashing to work. (What will not work?)

The ECS harness are separate from the main the harness. (I have tried to read most of the topics regarding the ECS on the forum and everybody sems to say that the ECS doesn’t do a thing)

What changes is necessary to do to get the engine to run properly if I remove the ECS?

[dirkbalter]

I did it by changing to a 123 distributor and a different (older) throttle body. 

[lpeterssen]

Dear Friend

I do wiring harness restorations as a hobby/business.

Some months ago I restored for a customer a full wiring harness for a 280SL with the Emission Control Sub-harness. 

That was the first time I had to study it in detail.

If you fully remove the EC harness nothing will happen, your car will perform flawless.

The functionality of the EC harness is to cut fuel delivery to the injection pump when several conditions are met at the same time as:

1. Car is engaged on 3rd or 4th gear
2. Clutch pedal is not pressed
3. Intake manifold IDDLE switch indicates that butterfly is closed (no gas pedal pressing)
4. Speed control relay, indicates that car RPMs are above the manufacturer set point.

If all that conditions are met, then the fuel cutoff selenoid on the back of the injection pump is activated, and therefore some gas is saved, and the environment is polluted less.

That is all.

If your are giving away your old harness I am interested.

Best regards
L.peterssen

[Lars G]

Thanks for the reply!

Will then go for removing the ECS.

Lars