I've recently undertaken the task of equipping my '75 98 Regency with Twilight Sentinel (while it wasn't available from the factory it apparently was offered after the fact by dealerships). While I have gotten the wiring sorted out, I'm not entirely sure how I'm supposed to mount the new headlight switch and rheostat (the old one was held directly to the dash with a single nut, though this won't work for the Sentinel specific headlight switch since it has rheostats in front of it).

My current line of thinking is mounting the rheostat assembly directly to the left-hand "faceplate" using a rubber spacer, thin washer and nut like so...




This is probably the only way I can mount it at if it is recessed any further back I wouldn' t be able to fit the ***** on. However in order to fit the faceplate back on I would need to cut out the old headlight switch mounting location...



and somehow devise a new mounting bracket for the new swich.



Does anyone have any ideas on how the dealerships may have originally mounted this or any recommendations?

 

Was Twilight Sentinel offered as factory option on the 1976 98 ?.

If not maybe it was a factory option it on the 77/78 Toronado if not available on the earlier ones ?.

I mention the Toro since they share the same instrument panel design.

EDIT -

Curiosity got the best of me & did a quickie google search.

Found a couple of 78 Toro's with Twilight Sentintel pretty easily.

Couldn't tell you whether they left the factory that way or got them after the fact.

https://www.mcecars.com/vehicles/129...do-brougham-xs

https://www.gatewayclassiccars.com/vehicle/tpa/2221/photos
(Canadian car)

 

It was, and also on Toronado and Cutlass. 1976 CSM devotes 8 pages to it.

Looks like you're missing a bracket.