328 failed exterior lights & headlights

I have a 1988 328GTS I purchased a year ago with 27K original miles on it...absolutely love it! Rosso Corsa with tan interior. Last Ferrari I had was a '62 250GTE 2+2 but that was during my college days (it was quite abused prior to me acquiring it = cheap). I am an avid do-it-yourselfer and am reasonably competent.

Recently my exterior (parking in the U.S.) lamps failed to illuminate when the stalk was twisted. No exterior lamps work, including the front, rear, license plate, side markers, as well as the dash lamps. Further, when the stalk is pulled downward (to illuminate the headlamp motors and lights), nothing happens.

Looking for the most simple fix, I read various forums and learned the "K" relay is troublesome. I managed to acquire a couple of new units to no joy...still nothing. My wiring diagram I found is poor in quality and I really need to secure a clean copy, the larger the better. However, anyone with suggestions would be greatly appreciated! My vehicle safety inspection expires the end of this month and I really would like to drive it (legally) after that!

 

Thank you, Spirot, for your response. I tend to believe you are on the right track as I performed a few more tests tonight. First of all, on my relay board, Terminals 30, 85, & 86 have 12VDC+...always. Secondly, when I jumper across Terminals 30 and 87b, the front and rear parking (U.S.) lamps illuminate, but not the sidemarker lamps nor the instrument panel lamps. Finally, when I jumper across Terminals 30 and 87, all of the exterior lamps (front/rear parking, sidemarkers, license plate, and instrument panel) illuminate.

When I applied a third jumper which applied power to both Terminals 87 and 87b, there was no difference...all of the lamps remained illuminated. However, the main beam headlamps would not turn on nor would the motors raise the headlamps. After reviewing the schematic again, it appears as if the parking/headlamp combination switch completes the circuits to allow the individual relays for the headlamp motors and headlamps to energize.

Bottom line is it is time to look into removing the combination parking/headlamp switch. Anyone with knowledge is encouraged to reply. My cursory glance indicates I must first remove the steering wheel (about 6 Allen-head screws?) which will expose be a large nut (my 911 is set up this way). I wish to be careful and not damage anything...and the steering column shroud...does it have to be removed or will I be able to access the combination parking/headlamp mounting screws at this point?

 

Thanks, y'all, for the suggestions and link. I thought I had seen the link before but could not find it. I am printing it off so I don't "lose" it again! Tomorrow I will try to remove the end of the light stalk...I believe the one depicted was a 308 and mine is a 328...unsure which end I should use a razor on but I will try both tomorrow. So tired right now I'd probably accidentally cut myself. My father always told me, "Son, if you don't draw blood when working on a car, it probably won't run right". And I'm sure most of us have the smashed/cut/bruised/burned/scarred hands to prove it....

 

Okay, okay...I've seen the link and Verell is definitely the man! I will attempt to carefully remove the stalk this evening taking every precaution to not lose any parts. My only request is that Unobtainium Supply Co. fill the parcel with upsidasium to lessen the shipping weight....