Wiring a SBC in 78

GAZRNR

Posted February 16, 2003

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Posted February 16, 2003

I am at the point of making my wiring harness for my carberated SBC/T56 conversion. I will be using the stock GM HEI distributor. Got the L6 & trans out and like everyone who has already done this on a FI Z wondering what I will do with all the wires on the left side of the engine bay. These appear to be the FI wire harness.

The wiring for alt, temp switch and starter seem straight forward. The fuel pump, distributor and A/C system seem to be my points of concern.

1) The wires that went to the coil are colored Blue for - and Black with White stripe for +. Can the Black with White stripe be wired to the Red + wire from the GM HEI dist and can the Blue wire be wired directly to the Neg terminal on the dist? If this is done will the tach work after the 15K resistor is installed? Do you keep the stock in line resistor and run the 15K resistor or pull that resistor?

2) After unplugging the computer can this wrie harness be removed as 1 unit by unplugging anything else connected under the dash? Is there any part of this harness that is needed to keep the other circuts working properly?

3) I marked the wires in disassembly and it appears that what is needed is on the right side of the engine bay. I plan on installing the fuel pump cut off pressure switch as JTR recommends, do you retain the fuel pump control relay and fuel pump relay that are in the relay bracket box on the fender? Is there a single wire that needs to be isolated that I can run from the oil pressure switch to the fuel pump?

4) The Z has stock A/C but the system has expired, at some point I want to run A/C using a GM pump and would like to use as much of the stock control setup as possible. I believe that I need to retain the A/C relay & other A/C related connectrors but should be able to eliminate the remainder of the relays on that bracket. Has anyone done this successfully?

I would like to avoid using the "wire snips" until I am sure that what I am snipping is not needed and will not mess up another circut. Am I heading down the right path on this or is there a better way approach this part of the project? Any help would be greatly appreciated!