Topic: 67 San Jose Neutral Safety Switch Harness and Connections

[67gtasanjose]

According to the MPC, there was a running change of the Neutral Safety Switch that occurred at or around Mid-December, 1966 for pretty much ALL of the 67 model Mustangs, but I am trying to pin down the understanding of these changes and perhaps the related connections. For example, this unrestored example has the jumper harness between the main harness and the neutral switch (estimated build date based upon vin number is January, '67)

[67gtasanjose]

FIRST QUESTION(s):

Which cars got this adapter? Small block cars (C4)? Big Block cars (C6)? Cars built after the change-over? Cars built BEFORE the change-over and this one still is BEFORE and they were using up the parts?

Does the tachometer option play into this scenario in any way?

Perhaps, with this change-over or running change, did the user dash harness also get updated?

[midlife]

FIRST QUESTION(s):

Which cars got this adapter? Small block cars (C4)? Big Block cars (C6)? Cars built after the change-over? Cars built BEFORE the change-over and this one still is BEFORE and they were using up the parts?

Does the tachometer option play into this scenario in any way?

Perhaps, with this change-over or running change, did the user dash harness also get updated?

The only changes on the 67 underdash were related to single spade leads at the washer foot pump and a change of the turn signal flasher from fused ACC to direct ACC (or reversed in time).  Surprisingly, with all of the 67 running changes, the underdash harness was remarkably stable during the entire year's run.

[7R02A]

Richard, my car also has this jumper harness.  Car details in signature.  John

[J_Speegle]

Not that it helps but they did a similar thing (engine feed to firewall loom adapter) in 69. Looked like a fix until they got a corrected engine feed on those.

[67gtasanjose]

Richard, my car also has this jumper harness.  Car details in signature.  John

Interesting. Yours is a December built car, do you have a confirmed build date? (Marti Report)

I'll be posting some more images soon. I have 4 of the early style switches. (Two originals and two Ford service replacements) It seems some of these early, 2-connector types have a blue connector (with a male & female bullet connector) and the other 2-connector plug in is a red connector. Then other switches and the ones available from NPD have a red and black connectors (hope this description makes sense)

NPD is selling two versions (see attached pictures) The early version, said to be for cars built BEFORE 12/15/66 have the two connectors (a red one and a black one) while the LATER version has a single connector with all 4-wires plugging in all at once.

The troubling part of this WHEN did the a.) colors change from red & blue to red & black and when exactly  did it change over to the later single plug-in type with all 4-in-one connector? (it does NOT LOOK TO BE 12/15/66...The image initially posted when this thread began was of a Mid-January projected build date is why I say this)

[67gta289]

Richard, my Dec 20 66 SJ 289 has the early style with the adapter harness.

[67gtasanjose]

Richard, my Dec 20 66 SJ 289 has the early style with the adapter harness.

Thanks John, your car was one I was hoping some original images might be available for since your Marti-Report supported build date is AFTER the alleged transition date. Perhaps what we need to be looking at is the TRANSMISSION tag date to pin down a transition time? I have a C4 trans out of a 67, also with the early style Neutral switch and the date code tag has 6M10B code (December 10, 1966) bolted on it (unknown what final assembly plant though).

I have some more pictures I took of the various original switches and OE Ford Service replacements that depict some interesting features of the color of the black or blue plug. (Please NOTE: some pictures taken WITH flash while others were taken w/o flash...WITH flash shows the truer coloring of the BLUE and BLACK differences as seen on my monitor and in real life) It seems some have or had a blue plug and others did not THIS INCLUDES the adapter harness, the adapter harness I have, the one end is definitely a bit blue when compared to the definitely BLACK plug on the same harness but not quite as blue as the NOS neutral switch I have. (Confusing a bit, the root of this thread's inquiry)

And one more sub-topic to point out differences in the plastic ring within the center of the switches. Some are black and others are white (different suppliers?) There are two USED ones still mounted on the transmissions, one of each. One is a black ring and the other is a white ring. The black ring is on the transmission I removed from my car while the white ring is from the dated December 10, 66 transmission that I have the adapter harness shown with.

I NO LONGER HAVE THE ADAPTER HARNESS FROM MY ORIGINAL and that switch is known defective. When it failed, I cut my adapter harness and by-passed the neutral switch so my original adapter harness is no longer available to see.

[ruppstang]

Our 11-04-66 SJ  C4 convertible does not have the adaptor and has a service replacement style switch. I suspect at some point the switch failed and the adaptor was removed. Which most likely happened to many cars. When I restored the car 15 years ago I was not aware of any difference so I left what I found.

I am working on a 2-15-67 Dearborn S code C6 fastback that has the two wire switch. Because of the late build date of this car, could have some of the early replacement switches have come with the adaptor? or possibly were some dealerships adding the adaptors when needed. BTW this car has a number of early car features such as a one piece fuel line, early brake lines, washer bag and short hood hinge. So it may have had the early switch. It is tough to pin this stuff down with all of the mix and match over the years.

[67gtasanjose]

FIRST QUESTION(s):

Which cars got this adapter? Small block cars (C4)? Big Block cars (C6)? Cars built after the change-over? Cars built BEFORE the change-over and this one still is BEFORE and they were using up the parts?

Does the tachometer option play into this scenario in any way? ***Does not seem to figure into any scenario at this time

Perhaps, with this change-over or running change, did the user dash harness also get updated?  ***seems to be answered earlier

It looks like this adapter is ONLY on the type with the EARLY style since it would not be on the later version (now that I have seen images from NPD on the differences)

For whatever it is worth...the ADAPTER can easily be removed and all will function AS NORMAL without the adapter as long as the backup lamp circuit is connected to the correct backup light pins (of the underdash harness) AND the starter circuit is also connected to the correct pins.

My belief is that the "adapter" was simply an assembly line part, used to prevent a worker from accidentally making the wrong connections since they are not color-coded correctly to match up with the STANDARD 4-wire under-DASH harness. As Randy (Midlife) says, and so it seems...ALL of the 67 model year underdash harnesses have the 4-wire type connectors made onto them. Evidently, somewhere in time during the model year, the Neutral switch was then updated to a 4-wire plug too (evidence suggests at this time that it was not Mid-December)

Question still remains as to "when"...

I will USE the adapter I have and I will try to determine which NEW Neutral switch best suites my application. So far, it looks as though I will be using the one with a black & red connector end...unless some unrestored examples prove the blue version is the correct one for my 11/2/66 built C4.  I have some time before I go to assemble.

Last, I will be deciding if the wiring "tag" ought to be GREEN or WHITE...another question mark

We could still use a few more unrestored example of the early version INCLUDING a few S-codes for more data.

It IS INTERESTING that in this image below of what is stated in another thread as a projected build date of Mid January, that the connectors between the adapter and the harness going down to the switch, both LOOK TO BE BLUE! (could be flash and/or camera angle). ALSO...the wiring tag wrapped around the neutral switch looks to be WHITE AND there looks to be another white tag around the adapter!   DETAILS, DETAILS!!!

[krelboyne]

I can't say for San Jose specifically, but early 1967 Dearborn cars also had the jumper, sometimes. I have found several examples where the two leads of the neutral safety switch were plugged into the molded plug with 4 pins directly.

[67gtasanjose]

Thanks Scott for this info ^^^

For whatever else it is worth, some of the USED items at WCCC (Scott's "home") have the BLUE connector on them (look at the used for the C6 application)
https://secure.cougarpartscatalog.com/store/Search.aspx?SearchTerms=C7W%20Neutral%20switch

[7R02A]

Richard, my car actual build date is Dec 16, 1966.  Friday it will be 50.
John

[midlife]

I still say that the engine gauge feed harness molded connector (red) mated to the black side from the underdash doesn't look correct to me.  I cringe whenever I see that...

[7R02A]

Also can provide a picture of a San Jose car with a projected build date from the door tag of Dec 30, 1966.  I was very interested in this adapter on this car to verify the originally of mine.  Had never seen one until I bought my car.
John