Marco I don't know if this will help but here is what I've found. You can see "Philips" brand name on the chime/buzzer. On the other side should be the part number like 461293. Not long after 77 - 78 the number changed to 470386. From the notes some changes might be needed. Looks like there are a few places that have this later number in stock. I'd like to know what they would charge hopefully not much. (Edit) Ebay listing has one for $49.00
http://www.ebay.com/itm/78-CHEVY-MONZA- ... 0315637633RPO ZJ9 is for the Auxiliary Lighting Group (Glove Compartment and Underhood Lights and Headlights-On Reminder) If you want and yours has it tell me what number is on it. These same places also have the part number 470386 except for NOS Parts Source. This place shows they have 22 of the 470386.
Collectors Auto Oroville Gm OROVILLE, WA 800-414-4462
I would also keep the one you have because it might be repairable? Brian
Part number 461293 & 470386 (NOS Parts Source does not have the 470386)
Chicago Auto Parts Bolingbrook Gm
815-614-3122
IL
Nos Parts Source
913.220.5746
KS
Llewellyn Obsolete Northridge Gm
818-363-5094
CA
Craig Motors -Napa Gm
800-224-8111
CA
This picture is Part # 470386
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