Newbie wiring / fuse box / "load shed/ relay switch "question.

daicos35

daicos35

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Ok, looking at my fuse box, below appears to be a load shedder (or a switch?), that sits between a power cable direct from alternator, and the power attachment cable to the fuse box (into fuse 9 on mine, thick green/pink wire)..

I assume this protects the whole fused system, by regulating /shedding the power going into it, or does it also act a switched , when ignition is switched on?

I cannot work out how it acts as a switch?

From there my only question is why do I have another cable direct from the alternator that does not go through any type of load shedder (or switch?) , going into fuse 5.

Assume this is clearly "always on" power (clock etc etc).

Sooooo,,

I cannot work out how the pictured below, acts as a switch, so why is it attached between one line from the alternator, and not the other line from the alternator?

Thanks in advance...
 

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Have you looked here with relays and wire colors?

Coupe Wiring and Relays

This Thread will attempt to display the wiring legends, diagrams and relays for both euro and US versions with photos and descriptions. 2800CS Early (Feb and Jun 1970) 1) Wiper Delay: brown/black (2), green/black (2), black 2) Wiper Changeover: green/black (2), brown/red, black (2)...
e9coupe.com e9coupe.com

What year (build date or with sardine can motors?)
 
Some comments - I believe the load shedding relay is on, unless the starter is engaged. When the starter is engaged, the load shedding relay disengages certain things (headlights, heater fan, windows) in the car so that they are not drawing power while the starting is attempting to start the car. Once the car starts, the relay returns to its
"normally on" state.

As to your fuse five comment: The fuse block in our cars acts as both a holder for the fuses and a power distribution block. Thus, if you look at the back of this fuse block, there are four spade connectors in the red area behind fuses four and five. Anything connected to any of these spade connectors shares unswitched and unfused power. The red and white striped connectors under fuse four share power, but subject to fuse four. The red and yellow spade connectors share power, but subject to fuse five.

Also, the area in green at the top of fuses six and seven contains three spade connectors. These are switched, and all three of these connectors share switched power.

Fuse Block.jpeg
 
is that color coding on the back face of the fuse block standard?. I have never seen it!! very helpful all makes sense,, the more i tinker, the more i understand
 
daicos35 said:
is that color coding on the back face of the fuse block standard?. I have never seen it!! very helpful all makes sense,, the more i tinker, the more i understand
Click to expand...
Well, standard in the way that my car had the paper as well. I'm not sure if the color coding is identical for carbed vs injection, Auto vs manual and/or other electrical differences. At least my cardboard pieces matches colour and striped color exactly to the one from Ohmess.
(I've got an EU 3.0 CS carbed, automatic, no airco, no front electric windows, May '73)

20220119_235020.jpg
 
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Look at all the spade connections..after all these years, the causes for many electrical problems.
 
Yes, that color coding is standard on the back of our fuse blocks.

As to the spade connectors being troublesome, they are actually very robust. The unused connectors in my picture are oxidized, and should be cleaned before use. But the ones under the connectors are very solid and allow excellent voltage flow. By far the bigger problems are using low quality connectors in lieu of the high quality ones BMW used, not making proper connections to the connectors and/or damage to the wires themselves.
 
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