280Z Ignition Switch to 5.7L TPI wiring

[sstallings]

Strotter, Deja, or anyone else who can help.

 

I think I've got most of the wiring for my '77 280Z to '90 TPI figured out at this point. BUT, I've been trying to determine if the BW (Black-White) wire for the Tachometer that JTR refers to in the Datsun Z - V8 Conversion Manual on pages 9-3 and 9-5 is the one that runs to the pos. (+) side of the Ignition Coil Resistor in the 280Z wiring schematic. I think it is, but I'm not sure.

 

HOWEVER, while researching this little detail, I noticed that every picture of a subsystem in the Diamond Pubs Z Repair Manual (see attached: ignotion003.jpg) shows the ingnition switch in line with the positive battery cable, providing voltage to some component or relay, putting it on the positive side of the circuit. And ther are only 5 wires going to the ignition switch, none of them B (Black) ground wires.

 

Back in the Helms GM Manual every circuit shows Pos. (+) power going from the battery or junction box to a component or circuit and for those that are only on with ignition, the ingition switch completes the cicuit by providing the path to ground (-) putting it on the negative side of the circuit.

 

So I have to ask myself (???) how is this Datsun ignition swith going to work with my GM engine wiring? What am I missing? It will obviously be fine for lights, instruments, etc., but it seems backwards for the engine harness.

[deja]

Sorry, I didn't use the Datsun ignition on my swap, went with push-button start. And the LT1 tach signal comes out of the PCM and since I'm using the Camaro wiring harness and TransAm gauges I didn't have to worry about that either.

 

But I don't know of any modern ignition switch that switches ground. Your battery negative is hooked straight to ground, the ignition switch switches +12v to run the car and too provide +12v to the starter. The ignition switch does NOT complete the circuit to ground, it merely interrupts +12v going to different circuits, like the starter and everything that is only powered when the ignition switch is on like the distributor.

 

I looked at the JTR manual and it refers to 2 different black/white wires, 1 sleeved and 1 not sleeved (leave it to Datsun to make it confusing). The sleeved wire goes to the Bat side of the distributor (positive side) which should somehow go the the ignition switch. The unsleeved 1 goes to the tach side of the distributor (negative side) and your tach.

 

Strotter, Deja, or anyone else who can help.

 

I think I've got most of the wiring for my '77 280Z to '90 TPI figured out at this point. BUT, I've been trying to determine if the BW (Black-White) wire for the Tachometer that JTR refers to in the Datsun Z - V8 Conversion Manual on pages 9-3 and 9-5 is the one that runs to the pos. (+) side of the Ignition Coil Resistor in the 280Z wiring schematic. I think it is, but I'm not sure.

 

HOWEVER, while researching this little detail, I noticed that every picture of a subsystem in the Diamond Pubs Z Repair Manual (see attached: ignotion003.jpg) shows the ingnition switch in line with the positive battery cable, providing voltage to some component or relay, putting it on the positive side of the circuit. And ther are only 5 wires going to the ignition switch, none of them B (Black) ground wires.

 

Back in the Helms GM Manual every circuit shows Pos. (+) power going from the battery or junction box to a component or circuit and for those that are only on with ignition, the ingition switch completes the cicuit by providing the path to ground (-) putting it on the negative side of the circuit.

 

So I have to ask myself (???) how is this Datsun ignition swith going to work with my GM engine wiring? What am I missing? It will obviously be fine for lights, instruments, etc., but it seems backwards for the engine harness.

[sstallings]

Deja,

Thanks for the quick reply. It looks like I'm reading the GM information incorrectly, so I'll go back and sort that out. Thanks for the clarification on the two BW wires. I interpreted the JTR instructions in such a way that the unsleeved wire was only used on 240Z tachometers. Since I have the 280Z tach, I assumed I didn't need that wire. Unfortunately the JTR manual is specific for carberated V8 swaps, so a bit of interpretation is required to apply it to a TPI swap. But I have the JTR TPI/TBI manual as well, and I'm trying to make sense of the details in both. I'll get there eventually.

Thanks again,

Steve

[deja]

You have a HEI distriutor so follow JRT's instruction for that.

 

 

Deja,

Thanks for the quick reply. It looks like I'm reading the GM information incorrectly, so I'll go back and sort that out. Thanks for the clarification on the two BW wires. I interpreted the JTR instructions in such a way that the unsleeved wire was only used on 240Z tachometers. Since I have the 280Z tach, I assumed I didn't need that wire. Unfortunately the JTR manual is specific for carberated V8 swaps, so a bit of interpretation is required to apply it to a TPI swap. But I have the JTR TPI/TBI manual as well, and I'm trying to make sense of the details in both. I'll get there eventually.

Thanks again,

Steve