electrical and ignition Wiring Help Needed - New Photos

[gliding_serpent2]

Thanks Jim and Bill. So this tells me that this "rogue" connection was probably always loose (tucked away)post rebuild, and that I just found it because I went looking. I feel a bit silly for not coming to this conclusion earlier, but this was probably spliced into the harness back when the car had dual weber 40's put in, and never removed.

 

AS mentioned in my previous post, my rebuilder was confused by it also and opened the harness, and connected the correct lead to the cold start valve.

 

I will unwrap the harness as needed and see if I can remove this spliced wire. I may order a new harness to clean things up as I do not recall seeing the above photographed ground. I will verify tonight.

 

Again, thank you both for all the help... invaluable stuff. 

Edited July 18, 2013 by gliding_serpent

[bnam]

Per my wiring diag (74Tii) there is one unused plug labelled "terminal 50" (item # 21 on the diag).  However, it is with a black wire.

 

The other terminals are:

#20 (connects to power from starter and is also black wire)

Green white wire and female connector to connect to the fuse block

Connector at timer relay

Ring terminal for ground on brown wire

Brown wire + Red/White wires to starting valve

Brown/white + Black/white wires to temp/timer switch

 

On the diag you posted, the middle one outlined in green is the ring terminal for ground.

The 2nd upright wire on the left is the power and that little bump in the middle is the unused connector "terminal 50"

 

None of this is white.  You may want to pull out this harness and see if anything else was added by PO.

 

Byas

[gliding_serpent2]

No PO, just previous work. I am almost 100% certain it was for the carbs low pressure fuel pump.

[PaulTWinterton]

Confirm that you have a connection to the cold start injector on your throttle body. That would make the most sense.

[PaulTWinterton]

Read your posts again so disregard connection to cold start injector.  It appears you have connection.  You might want to test to confirm that it works.

[gliding_serpent2]

Taking apart the harness for the mystery wire. I suspect it powered the low pressure fuel pump for the old carbs. A splice job.

Wire to thermo switch, cold start injector... And our mysterious friend. You cant see it here, but the thermo and cold start lines have been spliced to red and black lines.

Ground goes to the wrong location. Note, old fuel pump for carbs was mounted in this region. Note other end of oem wire splice to non oem red and black wire. Extra length needed for re-route for fuel pump.

Line from wiring harness taped to run with cold start and thermo wire. Connects with main harness.

I will put the ground in its proper place and separate the extra line for now. I will order a new harness as this one has been spliced with a lot of extra wire. Will save with my webers.

[gliding_serpent2]

Extra line wrapped into the harness....

Any thoughts where this goes? Different harness.

Back where it should go....

[Conserv]

Any thoughts where this goes? Different harness.

image.jpg

Square taillight cars have two similar (spare) plugs on the radiator bulkhead for use with fog lamps or driving lights. One is powered only when low beams are on; the other is powered only when high beams are on. I didn't think that round taillight cars had these but I've been wrong before, so it might be worth checking your electrical diagram to see if your system had an extra terminal(s) for future use.

Regards,

Steve

[mikesmith]

Model 71 schematic suggests just one fog light connector, consistent with what I see in my car.

[gliding_serpent2]

Good to know guys

[jgerock]

What's that number "4" painted in the center section of your hood?

[gliding_serpent2]

What's that number "4" painted in the center section of your hood?

After my dad bought the car in 73, he took it to mosport for what was probably the first bmw high performance driving course (at mosport) in 74'. Every car was given a vinyl number. Dad was #4. He had fastest lap, and fastest average laps. He kept the number, and i plan to do the same, however the underside of the hood is unsightly and badly in need of a restoration. Likely this fall, or next year. I will keep the number, or get a new sticker.

[PaulTWinterton]

Roundies only have one foglight connector above the battery.