Help - Behind the dash yellow and blue wire? Any ideas?

[71Dormobile]

OK found this baby tonight behind the dash on my 71 Dormobile.
partailly stripped out gauges etc during the resto and most things have found a home but not to sure on this one, anyone got ideas or a wiring diagram please?

 

[Harlequin]

wiring diagrams.....
http://www.thesamba.com/vw/archives/info/wiringt2.php" onclick="window.open(this.href);return false;

 

[type2tattoo]

I think its the oil pressure light/switch? ... or the brakes or internal lights, door stops etc?