Brake light switch composition and nut question

[Gary B.]

Re: Brake light switch composition and nut question

3886906 switches.

Gary

[Joe L.]

Re: Brake light switch composition and nut question

Way back in September of 2002, Pete Lindahl wrote the following:

“…the '66 Corvette AIM lists a P/N 3825257 Switch Asm- Stop Lamp and 1993509 Opt. (optional). The 1993509 switch was available as a Delco Remy and Chevrolet SERVICE part and is the metal switch. I'm assuming that the 3825257 is the plastic switch…”

I bring this up because, like my ‘66, multiple people have reported in DB postings that their ‘66s had a white plastic brake light switch. If those plastics switches are original to those ‘66s we know those switches can’t be GM 3886906, which also is a white plastic switch that was available as a service replacement part, because GM 3886906 was supposedly introduced on Aug 8, 1966, for use in the 1967 model year. GM 3886906 would not have been available in time for the ‘66 model year production.

So why are there so many ‘66s with white plastic brake light switches? The idea that those reported white plastics switches in ‘66s are later service replacements (GM 3886906) of failed original metal switches doesn’t make sense because years prior to ‘66 would also have failed metal switches that would have been replaced with the later, plastic style, service replacement (GM 3886906).

So, back to Pete’s posting and his assumption about GM 3825257. How do we know that GM 3825257 was not a white plastic switch? If it was, then some ‘66s could have gotten a white plastic switch, GM 3825257, while other ‘66s could have gotten the metal version, GM 1993509. That would explain the observation from multiple ‘66s owners that their cars have white plastic switches.

Gary

Gary------


The GM #3825257 switch goes back to 1963. No plastic switches were being used that early so the3825257 switch has to be metal-bodied. As I previously mentioned, I believe the 3825257 (Chevrolet part number) and 1993509 (Delco part number) are the same switch.

By the way, I have no doubt that the plastic switches are original to some 1966's even though it may not be recognized in the AIM.

[Gary B.]

Re: Brake light switch composition and nut question

Let me give a little more background about my curiosity about the brake light switch for ‘66. I’ve followed the description of the brake light switch in the ‘66 JG for many years. Here’s the history of the text in the ‘66 JG:

2nd JG edition (1994): “The brake pedal light switch has a white plastic body.”

3rd JG edition (1998): “The brake pedal light switch has a white plastic or metal body.”

4th JG edition (2004): “The brake pedal light switch has a white plastic or metal body.”

5th JG edition (2010): “The brake pedal light switch has a white plastic or metal body and radio equipped…”

6th JG edition: “The brake light switch has a metal body and radio equipped cars…”

Note that the 6th edition eliminated from mention the possibility of a white plastic switch. This struck me as odd because my ‘66 has what appears to be its original brake light switch, of white plastic construction, with what looks like 58-y.o. patina. In talking to all previous owners of my car no one told me they had to gave the brake light switch replaced.

Over the years I have read or talked with half a dozen ‘66 owners who describe a comparable looking white plastic switch in their ‘66s. This made me wonder what’s up with the change in the JG. Which undoubtedly will have some ‘66 owners replacing their white plastic switch with metal switches.

In searching the DB archives, I first found Pete Lindahl’s 2002 posting with his assumption that the first GM part number called out in the ‘66 AIM, GM 3825257, was a white plastic switch. For those of you who knew Pete, he wasn’t at all prone to speculate with no evidence. So, I can only assume that Pete observed multiple ‘66 with white plastic switch that looked original to those cars.

In further searching the archives I found this posting by Joe L. on Feb 7, 2010.

“GM #3825257 was never a SERVICE-available part so it must have been PRODUCTION-only. I'd say there are 2 possibilities:

1) The 3825257 and 1993509 are exactly the same. In other words, 3825257 is a Chevrolet part number for the Delco-Remy 1993509 switch, or;

2) The 3825257 is a switch sourced from a non-GM entity and manufactured to a Chevrolet specification (or, a non-GM entity specification referenced in the 3825257 specs). If this is the case, then the 3825257 is likely configured completely different than the 1993509.”

Given that GM 3825257 was never available in service, we are never going to find an NOS example in a box with a part number label. So, I repeat my question from my posting from yesterday evening. How do we know that GM 3825257 was not a white plastic switch that preceded the introduction of another version of a white plastic switch (GM 3886906) on Aug 8, 1966? Could it be possible that 1963-1965s, and some or most 1966s received the 1993509 metal switch, but some ‘66s got a white plastic switch? If GM had white plastic switches available as of Aug 8, 1966, then surely the technology existed before that for a non-GM entity to make a white plastic version of the brake switch. And for whatever reason no such switch was made or used on the production line until the 1966 model year, even though the part number goes back to 1963. Maybe GM was able to exclusively use the metal Delco Remy metal switch until some supply problem happened in 1966. If we reject that possibility of a white plastic switch existing prior to Aug 8, 1966, then we are faced with having to explain why so many ‘66 are found with period-correct appearing white plastic switches.

I believe there is more to this story than what we currently think we know.

Gary

[Ronald L.]

Re: Brake light switch composition and nut question

Gary,

All these questions are answered by reading the change log on the print(s).


Next -
The aim should have some clues, like use this switch with radio equiped RPO...however as we know, what was mass produced does have gaps, omissions.

[Gary B.]

Re: Brake light switch composition and nut question

Gary,

All these questions are answered by reading the change log on the print(s)...

[Harry S.]

Re: Brake light switch composition and nut question

Just went through my parts box. I can not recall if the switch came out of the box marked 1998667. The 1993509 is unopened.



IMG_5783.jpg

[Gary B.]

Re: Brake light switch composition and nut question

Harry,

The switch you show looks like the 1961-only switch. Check out this 2011 posting by David Luikkonen.

https://www.forums.ncrs.org/showthre...568#post532568

Gary

[Harry S.]

Re: Brake light switch composition and nut question

Gary, it does resemble the part in post #23.

Number 23 on the Bakelite end.

IMG_5784.jpg

[Ronald L.]

Re: Brake light switch composition and nut question

Gary,
There are many prints out there, who has them and what happened to the stashes of some members recently departed, not clear.

However - the first 66bb I restored in 1980 was by looking up prints and replicating finishes, there was no guess work, its all there.

They have all the detail necessary to fabricate the part and the first thing they start with is the part number.

[Gary B.]

IMG_1796.jpg

Gary

[Harry S.]

Re: Brake light switch composition and nut question

Gary, I understand about the mold number. The question is what is the part number? We will probably never know.

[Gary B.]

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[Harry S.]

Re: Brake light switch composition and nut question

Per Rich ---> 1963 Switch 3825257 Nut 107825

Just checked both 63's, the nut is incorrect. Anyone have a source for 107825?

[Gary B.]

[Gary B.]

Re: Brake light switch composition and nut question

Harry,

Jack Morocco just sent me this, which he found via GM Wiki.

IMG_1879.jpg