heaterbox terminals 2 tabs vs 3 tabs plus ground, ID please

[jerry]

folks, i've got an identity crisis regarding which heaterbox is appropriate for my '71 6-fuse car.

i'm pretty sure that my mid-71 12-fuse car requires a heaterbox with 3-female connections and one male ground tab. i'm referring to the tabs on the upper left of the actual heaterbox.

i have a box with only 2-female connections and one male ground tab. i'm beginning to suspect that this particular heaterbox is for a VERY early 02 and may have come to me from the junkyard years ago. it's been awhile since i did a batch disassembly of my stash and now i'm having doubts as to what goes where.

i'm trying to rehab all my heaterbox requirements in one fell swoop

does anyone know for sure if the 6-fuse 71 02 uses the 3-female or 2-female terminal heaterbox

btw, i tried the search and reviewed the heaterbox writeup....

[jgerock]

According to Mike Macartney's restoration book, the "early" cars with the smaller I.D. heater valve and hoses used a 2-speed blower with these wire colors:

Left to right on heater box terminals:

Green/white

Green/red

Brown (ground)

According to the wonderful 12/2002 Roundel article "The Car of the Year of the Car" by Phil Marx and Mike Self, the heater blower was changed from 2 to 3-speeds in 1969 (around VIN # 1664761). This also coincided with other upgrades such as 4-piston front calipers, short neck diff, headrests, etc. This article also points out the Modell 71 changes included "Heater core, valve and hoses enlarged" and "Fuse box now has twelve fuses versus previous models' six".

So, based on this info - a 1971 2002 should have the larger heater valve and a 3-speed heater blower switch.

Here is the wiring for the 3-speed box from my car. Note the resistor values (in ohms) for each of the three speeds.

[jerry]

thanks for the help. i am convinced that this box was likely from the 68 1600 that was given to me a couple years ago. i noticed that the PO removed the heater switch and moved the hazard switch to its location, when the dash was replaced with a one-piece.

now i'll need to find my stash of early switches. the loose wires for it are merely dangling.

looks like the original switch has four inputs. the wires get lost in the harness and emerge as just two outputs with a ground wire emerging from another nearby location.