Identify these mystery wires, win a prize! (engine bay)

[shenan-agon]

Snooping around my engine bay, I noticed the following - left side, near the coil & double relay box:

1. Red circle: there's a red wire coming out of this melted-looking yellow connector that's not hooked up to anything. Both red wires terminate at a single male spade terminal, which mates with the green/yellow wire through the connector (and both the intact red and the green wires disappear into other bundles). I pulled the sheathing back on the other red wire, and there's not another broken wire end or anything back there. The mystery wire has what looks like a female bullet connector on the end of it.

2. Green circle: this one has a female spade connector on the end of it, again not connected to anything. It comes out of a sheathed bundle with a couple other wires; some going to the coil, some to the double relay.

Simple question: should either of these be connected to something? I'll try digging through the Bentley wiring diagrams, but have a feeling you guys will have a quicker answer...

Bonus question, while we're on the subject - what's this connection for?
(similar area, along the back firewall to the right of the junction box)

(Oh yeah, the prize - I owe you a beer. If you're in Portland, or somewhere along the way up to the San Juans on our trip in 2 weeks, said prize may be claimed in person. Otherwise... I am not responsible for airfare.)

[blakeck2]

pic two might be oxygen sensor but im just pulling that out of my ass
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1986 Vanagon Syncro GL, westy interior, GW 2.4 and all locked up

1973 Thing

[blakeck2]

one might be to ac compressor
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1986 Vanagon Syncro GL, westy interior, GW 2.4 and all locked up

1973 Thing

[syncrodoka]

The red one goes to the pfetzer valve and the green one goes to the muffler bearing.
OK, I lied. I have no idea.

[syncrodoka]

The only big green wires that I remember in the engine bay are for the O2 sensor.

[blakeck2]

[shenan-agon]

Hmm...green wire ---> AC compressor might make sense, since my van has a defunct AC system with no compressor currently installed. Keep 'em coming...

[tencentlife]

The initial toasted triad is the remains of a hastily-repaired AC compressor clutch connection, the small green/white wire joins it to send signal to the idle speed control that the AC comp is running.

The second junction is the rpm signal to the idle speed control, this should be disconnected when tuning base idle speed at the throttle body.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[shenan-agon]

[tencentlife]

Yes, the slagged-out red wire circled in your pic would have gone to the AC compressor clutch.

It was late and I was tired so I missed the green circle, but the fat green wire? Oh, come on, you know what that one is, everyone knows that one. I'm gonna toss that up in the air and see if someone else will swat it down, hopefully someone close to you who can collect on the beer, especially if they can provide appropriate admonishments for why it isn't conneced to anything.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[shenan-agon]

Wait...that's not the O2 wire, is it? It was dark when I was digging around last night, so I didn't investigate too thoroughly. I replaced the O2 sensor a couple years back - plus, I thought the green O2 wire was a coax, and had something other than a simple spade connector on the end...

[tencentlife]

[shenan-agon]

Well, now I'm even more confused - like I said, I've replaced the O2 sensor, and thought I originally had everything hooked up right

I'm guessing that connection may have come loose at some point - I'll have to investigate...

[shenan-agon]

Update - I'm not crazy! Not as far as you know, anyway.

So that wasn't the O2 wire after all - see pic:

...though I can understand the confusion from the dark pic I posted before. The thick green O2 sensor wire is connected as it should be - which still leaves the mystery of this slightly thinner green wire with a spade connector.

I'm currently trying to swap a tach into my van; it wasn't working at first, and for a moment I thought I got lucky and this was the tach wire that's supposed to hook up to the coil. But no - it doesn't have any continuity to pin 9 on the cluster connector.

So...any other guesses?

[shenan-agon]

Mystery solved!!!

Since I know you were all hanging on the edges of your seats for the exciting conclusion:

Turns out it was the tach wire - while trying to trace down wire continuity in my earlier troubleshooting, I had pulled off one of the connectors on the back of the fuse panel and forgotten to plug it back in. Oops...with everything hooked up correctly, that green wire terminates at pin 9 on the cluster connector. I just popped the loose end into the empty slot in the plug that goes to the coil, and BAM! I ended up killing two birds with one stone - solved the wire mystery and got my new tach working!

I will now go pour myself a beer. Thanks guys...