What about the extra electrical parts after 350 upgrade?

[Guest Anonymous]

I have removed the old 6 in my 78Z and last night studied the owners manual wire diagram.

I labled as much of the wiring as I could.

I removed the computer and fuel injector wireing harness.

But I see a lot of "stuff" that seems to be left over from fuel injection system, much on the wire diagram did not expain what it was, only a short label giveing the part a name.

I have become concerned I may be over my head.

Please give me some advise......

Thanks

Terry

[DavyZ]

I am assuming you are going carbed now? Yes? Well, most of that wiring you can just cap off. According to the JTR manual, there are only a few wires going to the engine compartment that are needed. You do have a manual, yes? I would locate those wires as mentioned and cap off the rest. If I knew exactly where they cam from, I would cut them back--but that's only knowing for sure I had all relevant wires already hooked up to my working engine. Just food for thought.

 

Davy

[Dan Juday]

Don't cut and cap anything yet. Get bold after the V8 is running. Get those 10 or so wires you need and separate them just like it says in the JTR book. You do have the JTR book, right? You MUST have the JTR book. You're not over your head, you can do it! Just read and re-read and then read it again. Most sections I had to read at least 4 or 5 times before I figured it out. It's really not as complicated as it seems right now.

[Guest Anonymous]

Agreed, even a electrically challenged nerd like me could do it, pretty easy. Only one bit of confusion for me (and I know Blkmgk mentioned the same thing). JTR mentions looking in a bundle that is on the Passenger side for certain wires. Well, it ends up, that harness runs through the radiator support frame, across the front of the car and ends on the drivers side (the coil/ instr. sender wires), they are on the pass. side, but don't end there, I did have to route the wire back, to that side. Not a big deal. I also couldn't find the fuel pump wire, but I ran my own instead, no large thing. They're little hand drawn diagram despite looking a little rough is actually pretty accurate. Give it a shot, and if you need help, hollar, theres so much help here its scary.

 

Regards and good luck,

 

Lone

[QWKDTSN]

I have one question about wiring while we're on the topic - I removed a couple of wires from a switch on the Datsun tranny, reverse lights or something I presume, and they're never mentioned in the JTR manual. All they say is "hook up neutral safety switch and reverse light switch" or something along those lines in the Installation section. In the wiring section there's no mention of what to do with these two wires, I believe they are red and blue or red and black. I also can't see them in the pictures in the book where they are in my car, hanging down along with the starter wires.

[Guest Anonymous]

Yeah I know which ones your talking about. There are 4 wires, the ones that are red/blue are for your reverse lights, the other 2 I jumped together as originally I think they were neutral safety switch wires. My car's manual now, so that wasn't a issue, thats why I plugged them together (I think these are like Black/Yellow as I recall).

 

Regards,

 

Lone

[pparaska]

I hope this doesn't come across wrong, but there's a safety issue here.

 

Even if (and maybe because) you are doing a manual install, I feel you should use the neutral safety switch, or a add a clutch switch. Reaching into the car to turn the key while working on it and having the car in gear could be disasterous if there's no neutral safety or clutch switch cutout for the starter and the trans is in gear.

 

Just trying to help.

[Guest Anonymous]

Good point Pete. I ALWAYS make it a habit of stirring the tranny and making sure its in neutral before I start it. But... Your right, easy to get in a hurry and watch the car go into a fence or house or something.. (seems like Deja Vu on this topic? )

No offense taken, your right as rain. Kids don't try this at home!

 

Regards,

 

Lone

[Guest Anonymous]

The JTR manual I have shows a picture of what appears to be a 1971 or 1972 240. Your confusion might be coming from the fact that it would take a lot of work to make a 280 EFI car's wiring look like this picture. A 280 harness will look much different than this for many reasons. Don't worry about trying to duplicate this picture.

Before you get to far along, you should consider where the coil is going to be mounted, as well as how you will route the oil pressure/fuel pump safety wiring and perhaps the electronic choke heater wire. Basically all of these can be formed into one "new" bundle harness which can be routed straight up from the firewall opening, and up beside the battery utilizing the OEM wiring "clamps" under the cowl front face.

Start with the diagnostic connector (a sealed, unused pigtail near the coil bracket) and follow all its wires back to their origins and carefully cut them off. Tape up the junctions.

Now would be a good time to collect all the headlight and clearance light grounds and give them a designated ground point up front. You will find that Nissan got lazy and left us a paucity of ground points. Make your own. I like to ground the left side separately from the right side as far as lighting goes.

Now would be a good time to install good 10 gauge wire(s) from a designated relay power source up to the radiator for possible use in the future for an electric cooling fan assy. (No such wire exist in the OEM harness for this purpose.)

Dump the external voltage reg/alternator and all attendant wire associated with them. Leave the ignition power supply plastic "T" connector and the large "white" alternator, to fusible link wiring in place. You will probably have to add wire to the ignition supply wire to reach the alternator. You will need to join the original voltage regulator ignition power supply (from the dash charge bulb circuit) to the "T" connector.

Find a good used or rebuilt internally regulated Z car alternator and wire it as though it were in a 1978 280. Use of a Nissan type internal reg alternator will allow you to reuse most of the existing wiring connectors to the alternator.

Don't discard the radio noise suppressor capacitors in this process.

If you really want to clean up the driver side of the car's wiring, route everything except lighting circuits in the same manner as the coil wires etc. These would be water temp, windshield washer motor and brake warning) across the top of the fire wall. It is much shorter and get the job done in a sanitary way.

Place the temp sender location in the passenger side head (stock location for Chevy)and route the water temp wire up the existing fusible link harness bundle. The rest will follow the coil wire etc.

Try to leave any wiring associated with the AC for future use. You never know.

In one OEM automatic Z car conversion, we used the existing AC power wire to arm the Nitrous, and used the existing trans downshift microswitch at the gas pedal as the nitrous actuator. Worked slick.

Like Pete said, look to the safety end of things at all times, and don't be afraid to say "what if" when is comes to redesignating a wires useage for another purpose.

I HIGHLY recommend building a stand alone fuse holder (ATO plug in style fuse) and attaching it to the positive side of the battery to be used as the power supply source for any tests you make of the wirings function. If you have a direct short or what ever, the WORST that will happen is that you will blow the sacrificial fuse. A 20 amp fuse will handle most circuits load requirements nicely, but will burn out long before even the smallest 16 gauge wires in a dead short situation. These stand alone fuse holders are sold in the "HELP" sections for most auto parts stores.

You can do anything you like, just remember it is harder to re-install wiring once removed, than it is to simply identify it, and save it for later.

Use of loom snakes for temporary holders for the intended loom bundles works great. These split, corrogated plastic "pipes" are found in virtually all OEM Chevy cars in a variety of sizes.

Some converters prefer to never actually tape up the harnesses any more than at the main branching points, instead opting to cover the remainder of the wiring bundles with these corrogated loom snakes.

When you have sorted out all the bugs in the harnesses, then you can tape up the harness as a whole.

This is a bit of a bitch down under the battery near the starter with the engine in place, but I simple save all my small tape rolls for the tight spots, using the larger fresh rolls for more open areas where continuous taping can be had.

Don't get in a hurry. The motor installation will be a snap compared to the time it takes to rewire the harnesses.

This is not a comprensive list of things to do by any means, and if I forgot something its because the sixtys were good to me.