Missing "Working Current Relay"

[Matt113]

Very nearly there........but Houston, we might have a problem. We're hoping to start the engine after the rebuild on Wednesday PM, but I seem to be missing the "Working Current Relay", part 29 on the Emission Control System page of the technical manual. The other parts (9,4,5 and17) are all present and wired according to the diagram. I understand the "Working Current Relay" operates the fuel cut-off solenoid when taking your foot off the accelerator pedal. My, probably stupid, questions are:

1. Does it matter that it is missing?
2. Given it is missing, should the solenoid be disconnected? And if not where should it be connected to?
3. If I need to replace the relay, what is the part number and is it still available?

Spring is in the air!

Matthew

[alchemist]

My 67 230SL second (the lower one) solenoid on the injection pump was disconnected by the previous owner. In this case, the relay is not necessary. I also do not have your missing relay. I hope this helps.

[ja17]

Yes, it is not needed. Just disconnect the deceleration solenoid on the IP also.

[Matt113]

Many thanks! Does anyone know the part number and availability of the missing relay?

[ja17]

The relay is the same as all the other starting relays. It has four prongs.

[Matt113]

Thanks Joe 

[Matt113]

Ok, so here's the problem: I bought the relay, Part No A0005425819 for €175 from Mercedes, but my Czech mechanic says it should never had had one. I have a 1970 US spec 4-speed MANUAL 280SL, would this relay only work with an AUTOMATIC transmission?

Very nearly there with the renovation, just the soft and hardtops to do.......

Matthew

[TEJOLX47]

Hi Matt,

Sorry to bother you, but do you have a complete diagram with the wiring pins that you can share?
Many thanks
Francisco

1971 280SL