Mystery wire!

[Graunch]

Hi folks. A Saturday evening puzzle:  While tidying up some wiring in my ‘72 Twincam, and undoing some DPO “improvements”, I found this broken wire. It was inside the harness wrap (which looked to be original) in the branch to the starter. White with red stripe, 16 ga. No connection seems to be missing a wire that I can find. And the copy of the wiring diagram I’m using has no white with red anywhere!  Any bright ideas?  Thanks much for any help. 

[Arizona]

Not sure about that red stripe, but could it be a no longer needed vestige of the original cold start coil that has been replaced? That wire is just white on mine.

[Graunch]

Hmmm, interesting possibility.  I’ll investigate tomorrow. Thanks.

[jbcollier]

Here's the wiring diagram for your car:

http://www.lotus-europa.com/manuals/misc/electrical/tcfedc.gif

WR comes from the ignition switch to energize the starter solenoid.  What is hooked up to your starter's connections right now?

[dakazman]

Hi graunch, 
That wire looks like a white/ brown stripe which is the oil pressure sending unit on an s2 print.
I do not see an oil pressure sender on that print . To check it runs up to the oil pressure light.
Dakazman

[Graunch]

Thanks, but it’s definitely red.   Seems to be the original line from the ignition switch, replaced sometime in the past.

[dakazman]

I misquoted white / brown was for the low oil light.

If it going to the ignition switch the print shows white red to starter solenoid .

Dakazman

[jbcollier]

The oringinal wire was sometimes changed out due to hot no start issues: the dreaded “click” at the starter after a heat soak.  It caused by a variety of factors not the least of which is an undersized starter (spec’d for space reasons).  The best solution is to fit a starter relay close to the starter using the original WR wire from the ignition switch to control the relay powered from the battery wire terminal on the starter.  It sounds as though your PO just ran another, thicker-gauged wire instead.

[Graunch]

Thanks!   This seems to be what happened.

[Graunch]

I misquoted white / brown was for the low oil light.

If it going to the ignition switch the print shows white red to starter solenoid .

Dakazman

Yes it does!  I’m a dope for missing it.   It all starts to make sense now.  🤞

[jbcollier]

...because the original starters were undersized due to clearance issues, the Europa is a good candidate for a reduction gear starter. 

[BDA]

I second JB! I love mine!

[4129R]

When I traced the white with red tracer, it went to the Logic Box which only activated from the key start if certain things were connected. No idea what, but probably seat belts.

The late Federal wiring diagram shows a starter solenoid.

I have only seen 1 relay on the right inner wheel arch, which probably did this.