Topic: Rare Conversion Harness from 3 to 2 Speed Heater, 65 GT/Pony Car

[midlife]

Yesterday, I received a 65 GT/Pony Car underdash harness for refurbishment, and noticed an unusual feature: a jumper harness between the 3 speed heater version of the firewall plug to the earlier 2 speed heater firewall plug.  I was under the impression that the change-over from 2 to 3 speed heaters was simultaneous with the introduction of the GT (5 gauge cluster) version of the underdash harness, although I knew about a jumper harness for the swept gauge set of harnesses (sold by VA Classic).  I've seen about 35 65GT underdash harnesses, but never one with this jumper harness.  As far as I know, this jumper harness is not reproduced. 

The car is a Dearborn C code Pony Car (no fog lamps used), with last VIN of 664627





27, placing its date roughly 13-15 March 1965.  The yellow lead that typically goes into the resistor pack from the underdash harness was taped up.  Here are the pictures.  No label found on the jumper harness.

[jwc66k]

Smaller pictures would be nice.
Jim

[midlife]

Better?

[jwc66k]

Better?

Yes, thanks.
I'm lost. What are we looking at?
You say "GT/Pony car", it that the 65 special interior option (name ?)? I've seen one, a non GT but did not go into detail. It had the five dial cluster. Then this adapter is to use a 3 speed harness on a two speed heater and switch?
Pic 1 - The three wire lead off to the right is? The lower connector I assume is a firewall one. What's the part number on the tag?
Pic 2 - That looks like a fire wall connector with the "jumper".
Pic 3 - The fire wall connector closeup.
Jim

[midlife]

Yes, thanks.
I'm lost. What are we looking at?
You say "GT/Pony car", it that the 65 special interior option (name ?)? I've seen one, a non GT but did not go into detail. It had the five dial cluster. Then this adapter is to use a 3 speed harness on a two speed heater and switch?  Yes, this is the late 65 variant with the 5 gauge cluster that came either with the GT option or the Pony Car Interior.
Pic 1 - The three wire lead off to the right is? The lower connector I assume is a firewall one. What's the part number on the tag?  Three wire connector is the 2 speed heater switch, which is normally integral to the early 65 underdash.
Pic 2 - That looks like a fire wall connector with the "jumper".  Correct.  Notice that the underdash plug has the retaining locking tab already inserted. 
Pic 3 - The fire wall connector closeup.  Correct: this is the engine gauge feed plug whose configuration is unique to this year/model. 
Jim

I tried to find out when the transition from 2 to 3 speed heater occurred, and all I could find was VA Classic catalog says April 1.  I don't know where that date comes from. 

[midlife]

Part number on sticker is: unreadable due to the tape.