SPEED SOLENOID?

ScottAndrews

ScottAndrews

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I am not super familiar (yet) with carburetted BMWs.

In my noodling on the wire harness project, I became quite familiar with the CS wiring diagram. I noticed that there is a pair of relays and solenoids that appear to be driven by the ignition wire. Thes er labeled Speed Solenoid i and Speed Solenoid II.

Where are these located, and what is their function?

And another newbie question: Since my car is in storage on the other side of town, and I cannot easily got over there to explor myself, where is the "plug board" located, and is this where the various connectors from the engine bay/front harness pass through the firewall? Seems odd that they would not identify this explicitly on the wiring diagram.

TIA
Scott
 
The speed solenoids are located below the coil where the frame rail meets the front clip. They control the 2 solenoids on the firewall which when activated, open/close the vacuum supply from the carbs for emissions purposes.
 
The wiring harness passes through the firewall under the coolant reservoir near where the left fender meets the firewall. There is no plug board in our cars. The junctions you see on the wiring diagram are actually a series of double sided connectors that are installed together in front of and just below the fuse block.
 
Ohmess said:
The wiring harness passes through the firewall under the coolant reservoir near where the left fender meets the firewall. There is no plug board in our cars. The junctions you see on the wiring diagram are actually a series of double sided connectors that are installed together in front of and just below the fuse block.
Click to expand...
When you say "double sided connectors", are these bulkhead feedthroughs*, or does the harness pass through the firewall with some sort of grommet and then the plugs connect under the fuse box?

*Specifically, is one side fixed to the firewall, and the other detachable, or are both sides detachable and the feedthrough is a separate thrid piece? Likeone of these three approaches...

feedthrough.jpg


Thanks

Scott
 
Not bulkhead feedthroughs. The harness passes through the firewall as a wiring harness. The "terminal block" you see is actually a series of terminals that join spade connectors together. I don't have a pic from my car, but they look very similar to the set of twelve on this page: https://www.autoelectricsupplies.co.uk/p/blade-terminal-connectors. I believe the set near the fuse block has six connections v twelve in this picture.
 
Stevehose said:
The speed solenoids are located below the coil where the frame rail meets the front clip. They control the 2 solenoids on the firewall which when activated, open/close the vacuum supply from the carbs for emissions purposes.
Click to expand...

Emissions stuff, so US specific?

I do not remember having anything alike in that location, but as I have a swiss car, could that make sense?
 
Of the three, the bottom approach most closely resembles how it works in our cars, but instead of plugs joining the wires you'll find the type of connectors that Chris linked to above. The harness passes through the firewall and the connections are made on the interior of the car near the fusebox.
 
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