A couple of "WTF is this" questions with photos!

[Trimble Epic]

OK...

So I've been reading about this car non-stop for over a week, and I'm starting to notice some things wrong under my hood. So, please help me understand what I have!

First, what is THIS, and is it missing a cover and gasket? It really looks like it's supposed to have a gasket and something on top. But I'm not sure. What is it?

Second, I was looking at my PTU, and realized there seems to be an extra harness attached to it.. WTF? Like it has two copies of the same connector daisy chained together? what's going on here? This is abnormal, right? It's zip-tied to the upper radiator hose?

I'm gonna do some research to see what is supposed to be happening here, but this isn't in any of the drawings in the 300zx_1993_FSM ...

Edit: Oh yeah, one more question... My Tachometer isn't working.. intermittently. Every now and then it comes up and works for a few minutes. So, I suspect a corroded connector... Where does it connect?

[Ace2cool]

1. It usually has a square metal plate on top of it. My 2+2 didn't, and the cruise control worked fine. My TT has the plate, and the cruise control doesn't work. Probably the relay, but just saying that I don't think it really matters.

2. That's the subharness. It's fine. Your car came with the original silver PTU, and those were prone to failure, and were replaced on a recall basis. The new PTU has a different pinout/wiring, so they used a subharness to connect it. The only thing wrong is it should be mounted higher up, usually on the timing belt cover with a bracket.

3. Speed sensor is on the transmission. Farthest connector to the back.

[Trimble Epic]

2. That's the subharness. It's fine. Your car came with the original silver PTU, and those were prone to failure, and were replaced on a recall basis. The new PTU has a different pinout/wiring, so they used a subharness to connect it. The only thing wrong is it should be mounted higher up, usually on the timing belt cover with a bracket.

Damn, you guys know everything

So, I take it this means I have a newer style PTU now, and its less prone to fail? Thank you

[Ace2cool]

You got it.

[t.mcginley.jr]

My PTU subharness looks exactly the same. Its just ugly looking. Mine was actually zip tied to the upper hose too, but then again my upper hose was zip tied to the radiator instead of a clamp. Gotta love rednecks

[ThisIsSparTTa]

I had to cut that subharness out and do a direct solder job, which I hear isn't too uncommon. I was getting all kinds of problems localized to that stupid connector, so out it went, and so did the problems.

[Trimble Epic]

What kind of symptoms did you see before cutting out the sub harness?