New World Datsuns...

Bit the bullet tonight. After much debate, ordered the Wiring Specialties harness. $749, just another drop in the bucket, right? I'm very close to calling this project. I love the wagon, but if things keep screwing with me, she's going to be on the auction block like the Z. Don't want to do it, but I'm losing interest. Thing is, it needs to run to be worth anything.

And did I mention, when I looked under the car the other day, there was antifreeze? Bellhousing bolt. Don't see any leak trail though. Suspect the rear freeze plug I didn't change might have just bit me in the ass. Sigh. Someone tell me I'll finish it and it will all be worth it, please.....must....keep....faith!

Have you considered maybe an L26 with SUs??

Targeting information acquired.....coordinates set.....ultra huge missle launched! Wait for it!!

What would I do without you guys? If I had rebuilt the P79 head instead of decking the Maxima, I would have had a bitchin' motor no problem. Would have lowered the compression enough. Oh well, coulda shoulda, woulda.

Just harmless ribbing.
This will be cool once you get it sorted. Nature of the swap game. Takes patience and always 3x what you budget.

Lol, true that! It's 38 degrees and raining here. Woooooo! I'm inside cutting new trim to replace the trim Weasel chewed when he was a puppy. There's a lot to replace, the house looks like a disaster zone.

Yea, I cant say Im excited for all the issues I may come across... Stick with it, the car will be super fun.

Yeah man you’ll get it. Keep plugging away at it, you’re over the hump now.

It is a thing of beauty!! And I freakin' LOVE the warning tag attached to the harness, lol!

Finally wrestled the harness out. It would be a lot easier with the engine out of the car and the upper intake off, but f that noise. I should be able to carefully thread the new harness through, might be a slight pain but it's a lot more bendy than the old hard original harness.

Super good news: The water leak I thought was the back engine freeze plug turned out to be a heater hose the dripped behind the starter and the transmission strengthening plate to land on the bellhousing bolt. Looks like I won't have to remove the transmission, so that's a major plus!

So here's my current predicament. I have to run the new wiring harness through the firewall. I'd love to yank out the existing harness and put in the new one, but I need all those other little bits of wiring to work and I'm trying to disturb the original wiring harness as little as possible. And of course, the amount of room is very small.

The new wiring specialties harness has a slightly smaller rubber grommet, similar to the original. The loom is about 1 1/4" diameter, similar to what's there. I can technically cut a 2.5" hole right next to it, trim the original rubber grommet, and put it right next to it before it hits the incoming AC lines. It's just really tight. I'm debating two things:

1. Cut the existing rubber boot (which I see little rust spots forming around the hole edge, damn 80's non-rust prevention/crappy Nissan metal prep!) and run the wire kind of next to the original loom.
2. Other option, make a smaller grommet in between and seal the holy crap out of it once I have it where I want. Although, now that I'm thinking about it, I probably need at least a 2" hole to fit the ECU connector through as it's quite long.

OR: Do you guys have a better idea?

No ideas from me. You're there and we're not.
Can the harness only be fed one direction? Is 2" the smallest hole possible?

I'll have to measure the connector harness, but maybe 1.5", I don't know. It's definitely not a lot of room. If I trim a bit of the existing rubber, I can put it right next to it, but it's pretty crowded, and leaves a pretty big hole in the firewall.

I don't know how large the new harness is that has to go thru the firewall, but I would cut the rubber hole plug and try to put it thru the existing hole next to the already existing harness, I would not make another hole.
I have put several 720 wiring harnesses into 520/521 trucks, it's a pain and I have to remove the various electrical parts and plug them back in where they belong after getting the harness thru the hole, sometimes the larger plugs don't want to go thru because of lack of room, but I get them thru as I certainly do not want to remove the wires from the plugs, but that is another way if you have no choice.

I think you're right Wayno. Might be tight, but probably a better idea. I'll just have to silicone seal it on the outside really well. Probably use the right stuff and blend it in.

Ok, so here's the latest update. Since I'm having the ECU hopefully fixed for the race car, that left me with the wagon. So I started getting the harness sorted on that. First off, the harness is beautiful. Second off, Wiring Specialties' tech support sucks. I couldn't drag a straight answer out of 2 guys in 5 emails with multiple pictures. Short of it is, the way they have it routed in the diagram, it needs to have the intake off before the wiring is routed.

I already have the engine together so that wasn't an option. As the emails dictated, they basically said run it how you see fit. So I ignored the directions and ran it in the same spot as the original harness for the most part. Works like a charm, the wires are a little long, but better too long than too short, right?

Furthermore, the original ignitor is on the back of the valve cover. The wiring specialties harness moves it to just in front of the ECU, which is in cabin. So that's an annoying bundle to hide in the passenger footwell. I'm probably going to try and make a slit in the carpet and insert it with a ground strap attached to the front stereo fascia to ground the unit. I'm not sure how critical it is, but it was secured with 4 screws and a ground strap in the factory location. One large ground strap will have to do, because I literally have no place to mount it short of going through the trans tunnel or floor. I suppose I could make a little plate and then ground strap that. I might...anyway.

The next problem is the ECU is going to be right about where that big white connector is. Either way I look at it, I'm going to have to make a cover of some sort in the footwell. There just isn't any space to mount it unless I lengthened wires or ran it in the engine bay. We know how ECUs love engine bays. Jeep seems to think it's a great spot. No wonder there's corrosion after only 10 years. The big open spot where the wiring harness goes next to the original is going to be completely taken up by the heater fan assembly.

I had to run the auxiliary fuse/relay box through the glove box as there was no space. 910s just have no space!! Those extra leads I'm going to run through the middle behind the stereo and out up to above the gas pedal where there's a grommet that can accept more wires. It's going to be much easier running it out the driver's side where I can actually get up there without removing a fan assembly that took an hour or two to remove without breaking everything.

So if you're wondering, yes, this would have been much easier if I didn't care about A/C, or plastics, or interior. Basically much better for a race car or older Datsun with loads more firewall space. I don't know why this particular model is so bad, but everything is crammed in there. I'm going to blame the 80s, as much as I love them.

Long story short, not an easy install, though it should be.

You'd be done if you just LS'd the damn thing.

I have read quite a few reviews on Wiring Specialties as of late. Some say it just works. Some say they had to rewire a plug. Some say the whole harness had to be gone through to reseat all of the pins. But they all say its a very nicely made harness.

Nice work! Looks like somewhat familiar territory. I'll be building a false floor panel against the firewall in front of the passenger footwell for mine. Might seem hokey but Honda did the exact same thing for years. Once the carpet goes in, no one will know the difference.

DRIVEN wrote: ↑Mon Jan 06, 2020 5:56 am Nice work! Looks like somewhat familiar territory. I'll be building a false floor panel against the firewall in front of the passenger footwell for mine. Might seem hokey but Honda did the exact same thing for years. Once the carpet goes in, no one will know the difference.

Subaru did for a while too. Late 80s to mid 90s. Could be more.

I like the idea. There's not enough room up front, but I'm sure I can make one on the side.