sensor purpose-86 engine, 14 pin question

[inaminit]

Hello- I am getting ready to install an 86 engine into a 76 body. The next task is the 14 pin connector modifications. I have read all the 3.2 conversion threads here that I can find. Marc's site has been very helpful-he give a good discussion of his 14 pin mods. But I am struggling with the purpose of and the need for some of the pins.
On the 86-one pin connects to a sensor in the breather assembly-what does it do?
Also- On a 76 engine harness there are 2 pins assigned to the backup lights-what do these do inside the engine harness? The backup switch is on the trans-the connections are in the tunnel-it makes no sense to run the wire through the engine harness. On the 86 wiring diagram, the backup lights are operated directly from the switch. Why not hook the 76 up like that?
Thanks in advance for your answers!

[Chuck.H]

no-name, no-location writes:
>>> On the 86-one pin connects to a sensor in the breather assembly-what does it do?

Can you be more specific, are you referring to the barn door air sensor? Do you have the wiring diagram for the 1986, this should reference these wires.

Best,
Chuck.H
'89 TurboLookTarga, 346k miles

[E Sully]

The sensor in the breather cover should be the blower temperature switch. I used the back-date heat method in my 1973.5 and therefore this was not needed.

The reverse lights 12V power comes through the main wiring harness from the luggage compartment fuse panel to the 14 pin connector, goes through the engine wiring harness to the transmission switch, returns to the 14 pin connector again to the harness to the rear light housing. Wiring matched up from the '86 to my '73 no issues. The only connections in the tunnel would be for the later electronic speedometer sensor.

The only time I really care about location is when I want to know shipping in the Parts Forum.

[inaminit]

Thanks Ed- Your other posts on this topic have been part of my guidance system on this project. I spent much of Sunday PM going over the 86 engine and 76 car harnesses. In my case. power to the backup lights comes from a fuse in the trunk to the tunnel, then out the tunnel to the trans, where the switch is located, then back from the trans to the green yellow wire, then to pin 5 on the car plug. Pin 5 to pin 6 on the engine harness plug has continuity, Pin 6 on the car side is the gray wire to the backup lights. I just don't understand why they made the electrons travel so far out of the way. But it should work.
The breather switch on the 86 engine must have been designed towork in tandem with the control box. So, on the earlier bodies, the fan should be able to be switched from the defrost lever switches. Like you, I am going to ignore the breather switch. thanks for the post.
For the record-I am going to continue to use the name inaminit. Location is deep in the woods of Maine. As far as I know, there are no other Pelicans for hundreds of miles. Thanks to our host for this Board!!!