Instrument Panel Dimmer Switch Numbers & Date Codes

[Solarguy]

I have 2 gauge panel dimmer switches one I know is from an E body and the origin of the other is unknown.  They both look identical.  The part number in the parts book is 3420-865 which is NOT stamped anywhere on either switch.  Both switches have the following numbers stamped on them: 2947713 and 38073.  These I believe are supplier numbers? or alternate part numbers?  Each switch also has a unique 4 digit number  which I believe is the date code?  those numbers are 2509 on one and 2939 on the other. 

My question is on the 2509 switch which is the one I don't know the origin of.  If that is indeed the date code, that puts it at June 10, 1968 which is way too early.  Were these dimmers used in other Chrysler models or am I misinterpreting the stampings?  Is the 3420865 parts book number anywhere on these switches that I'm not seeing? Am I correct that all the Ebody dimmer switches the same, dimming the dash lights and turning on the dome light with a firm click?
Thanks

[anlauto]

2509 is 250th day of 1969

[Solarguy]

Thanks Alan.  I was using the 10,000 day calendar to date these, I take it that's incorrect. 

[6bblgt]

same part number (3420 865) is listed for all E-bodies 1970-1974

the part number (3420 865) in the Parts Catalog probably included the attaching nut (assembly# = switch w/nut)

2509 = 250th day of 1969 Sunday 9/7/69 & 2939 293rd day of 1969 Monday 10/20/69
I have a restored early switch from JS Restorations  dated 2029 = 202nd day of 1969 Monday 7/21/69

38073 would be Chrysler Corp.'s "vendor code" for the switch's manufacturer

[Solarguy]

Jim at JS Restorations emailed me and gave me the low down on the part number/date code deciphering on these dimmer switches.  I was erroneously using the mopar 10,000 day calendar to date them. 


This leads to another question I know you can answer @6bblgt, what is the 10,000 day colander used for? 

[Cuda Cody]

@Solarguy  this will explain some of the main things the 10,000 date is used for...

https://www.e-bodies.org/resources/mopar-chrysler-10000-day-calendar-date-code/1970-model-year-engine-trans/

Jim at JS Restorations emailed me and gave me the low down on the part number/date code deciphering on these dimmer switches.  I was erroneously using the mopar 10,000 day calendar to date them. 


This leads to another question I know you can answer @6bblgt, what is the 10,000 day colander used for?