Nate, good news, you can remove this one from your Christmas to-do list... 
While just now writing to describe how it made no sense, suddenly it made sense: This circuit forces on the low beams when the High beams are on. Is that a difference between US and Euro cars ?
I looked at a fuzzy picture under the dash of 1046 and saw that relay, but it didn't have the black terminal covers around the end and I just dismissed it as a modification...! See attached, I've been saving money on Christmas presents by proofreading a wonderful re-draw of the diagram (instead of shopping)...!
But as I see it;
- headlight power comes directly from the ignition switch to the first toggle switch, then to the indicator stalk via the Gray/Black wire--there is switched by the turn signal switch for High or Low beam, then out to the headlamps via fuses 1 and 4.
- The 'headlight flash' circuit bypasses the toggle switch; power sources from fuse 7 (brown wire, turning to Blue-brown at the junction). The "flash" connection in the Lucas stalk provides an alternate path to the high beams.
- The Carello relay 22.900.000 part (aka Sipea T5170) terminals 85 and 86 seem to be universal designation for the solenoid power, as well "87" seems to be common for "normally open" (and "87A" means "normally closed...).
This is simple, when the high beams are turned on, the relay closes and (using the power from F7) turns on the low beams.
(note the schematic refers to terminal 80/51, and the other markings I see for example the Carello look-alike 4263598 say 30/51 but at least there is really no other way to explain this relay...!).
Appreciate comments on whether it really all works this way ! The downside for the circuit is that yes, it seems that the current thru the "Flash" wire would get quite high when the parking light switch is turned off (since all the current would come from the F7 patch, instead of the normal operation current is shared between F7 and the ignition key path...)….Lee
