74 260Z wiring

[HLS30-08077]

Thanks, but that's a 240Z diagram. I'm actually the guy that makes the ZXP 280ZX alternator adaptor plugs that you've probably heard of and is sold at MSA.

I need 260Z wiring help. I know 240Z's and that's the problem, I need to learn more 260Z stuff.

 

Thanks anyways

Dave

[TrumpetRhapsody]

I'll take some pictures of my wiring when I get off work today.

 

I've done the 280zx alternator swap, but haven't figured out how to remove the shunt.

[zcarnut]

.... What or how do you remove all the Safety Interlock B.S. and still have everything work...

 

 

To disable the 260Z interlock see this recent thread:

 

http://forums.hybridz.org/showthread.php?t=151366

[sdawson]

Here is a drawing of the wiring for the 260Z voltage regulator compared to the 240Z. As I see it, the connections are very simular except for the BY wire (260Z Engine Revolution sensor wire). I have not completed this connection yet, so verify the connections before you do it. The wires are not in order as they are in the plugs.

Color comparision 240.260.doc

240Z Alt wiring with color.doc

[HLS30-08077]

So. After reading everything possible on the subject, studing the FSM's, diagrams, drawings and anything I can get my hands on...... Here's what I've done to my 2/74 260Z........

 

I completely rewrapped the engine harness and removed every un-needed wire. Those included the EGR wires, red foglight wires, added a 10 gauge ground wire in the middle of the front core support to be bolted to the support, The A/C compressor blue wire, small white and w/r wires from the shunt, the shunt, ALL A/C wires (yellow pressure switch wires, mag valve wires and A/C relay) Emergency switch and it's wires, etc, etc.

 

Interlock Module...

(Located in the uppermost area of the passenger side kick panel w/ 2) 6 pin connectors, I completely disconnected it.

 

Seat contacts and seatbelt contacts...

Disconnected because I will have aftermarket seats and a different model or style seatbelt system AND the wires all go to the now-disconnected interlock module (it'll have a roll bar and 4-point harness's)

 

Interlock Relay...

Located on the firewall and had 1) 2 wire connector and 1) 3 wire connector. The Black/yellow and the yellow/black (or solid yellow) need to be cut from the relay and connected to each other. The other wires are a ground and 2 control wires. I cut mine and fed them back thru the firewall.

 

Emergency Switch...

Located near the battery on the fender, 4 red associated wires, I disconnected the switch, cut the Y/B and the B/Y from the connector and connected them to each other. The black wire is a ground and not needed, the blue is connected to the B/W ign. wire inside the harness.

 

 

The dreaded SHUNT...

Since I won't have an AMP gauge, the shunt is pointless, as that's the only purpose I have found it to serve. The shunt's W/R 8ga wire is a tap from the Alternators 8ga wire. The alt wire goes to the green fusable link on the firewall, but not before it's split again and goes thru the firewall. After it's fused on the firewall, it's now a 10 gauge W/R that also goes thru the firewall as well.

The White 8ga wire from the shunt, goes to the Black fusable link on the firewall. After it's fused, it goes to the starter. There is an 18 gauge tap on the White wire, before the fusable, that goes to the VR.

SO, I cut the 2 large wires from the shunt and connected them to each other. Reason for this is simple, they are already connected inside the Shunt via a large peice of wavy metal. Which I felt could only inhibit amperage, so one less connection. The 2 small wires from the shunt were cut and fed back thru the harness and the firewall, to be cut off. They go directly to the Amp gauge, which I will toss and replace with a very small LED face volt meter, from a bad Car stereo Capacitor.

 

The only thing left is the Voltage regulator. If I had a question for the pros, It would be this.... Does the VR have anything to do with the Fuel Pump relays?

I know it has an alt. sense wire but wondered, if I connected the B/W and the W/B together as well as the W and Y together, tossed the black ground wire, what wires are left and where or what should I do with them.

 

Below is the remainig crap, you should have seen all the old tape, wires, connectors and crap that removed. Filled a grocery bag with junk.

 

Dave

[zcarnut]

...The only thing left is the Voltage regulator. If I had a question for the pros, It would be this.... Does the VR have anything to do with the Fuel Pump relays?...Dave

 

Yes. The “N” terminal of the voltage regulator feeds one of the two fuel pump relays. This is part of a safety feature that is needed when you have an electrical pump. When the alternator is rotating a voltage is generated at the N terminal of the alternator and voltage regulator. This is in case you have an accident where the engine stops but the fuel pump can still remain running and thus feed gas to a potential fire.

 

See Fig. EF-15 on page EF-7 and Fig EE-29 on page EE-13 of the factory service manual.

 

The later Nissan vehicles used an extra switch on the oil pressure sender instead of using the “N” alternator signal voltage.

 

On my 260Z when I (like you) got rid of the interlock system and went to an internally regulated alternator, I elected to just bypass this extra fuel pump relay (I like using the electric pump to prime my triple Webers). However, I can not advise you to do the same because this a safety issue.

[HLS30-08077]

So I used 3 different diagrams and the FSM to follow the Yellow wire. The Yellow on the VR is the same Yellow on the Alternators "N" connection. The Yellow wire is tapped and ran directly to the "Electric Pump Cut Relay #1".

 

So If I inderstand this correctly...

1) The relay will still be powered from the Alternator, due to the yellow wire being tapped between the alt. and the VR.

 

2) The White and Yellow need to be connected to each other. The yellow will receive power from the white, which is tapped to the White Starter wire. So the Cut Relay always has a (+) signal.

 

3) The B/W and W/B need to be connected to each other using a diode with the Cathode (striped side) on the W/B wire.

 

4) the Black wire is a ground wire and can be cut short.

5) the B/Y goes directly to the Interlock which is now disconnected.

 

BUT.... Connecting the White to the Yellow will make the Cut Relay STAY ON FOREVER. Both relays must work in order for the Fuel Pump to operate.

The B/W from the ign. goes to the #1 relay, then to the G/W which goes to the #2 relay, which turns into a B/W again and to the pump. The #1 relay has a Black wire which is always grounded and the other wire is the Yellow. If I connect the Yellow to the white wire, which is connected directly to the battery (fusable link then the starter) then the relay will always be on, and possibly burn out quickly.

 

So you see my delima. SO, Should the Yellow wire be cut from inside the harness and connected to the Alternators wire that sends a (+) signal when running? Or connect it to a relay that is only active when the Oil Pressure level is higher due to the engine running?

 

Any advice would be greatly appreciated. I think I might be on to something, or just confused.

Dave

[cruceno21]

I am working on updating my 75 280z to maxi fuses for my fusible link but I am not sure which wires go to what since all writes up out there are on 77-78 models. I might just wait on that (since my links work now) and do it once I go with an upgraded alternator and really simplify the wiring.

 

I bookmarked this thread. Good info and I think should be fairly similar to my 75 model.