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Hello all,

I'm doing the finishing touches of the installation(finally) to my 93' Suburban. What should be done with the old fuel injection harness? Should some parts of it that is not being used be clipped off?

I beleive in my case, I still need the computer because that help facilitates the cruise control. Othere then that, the only parts of the old wiring harness I'm using are the TEMP, OIL Pressure and Tach.

Chase

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Hopefully someone who's familiar with a late GM can give some tips. My best advice is don't cut anything off of anything until the truck is running, driving and has some miles on it. At that point you'll know far better what you can live without.

Most SMEC module computers send reference signals to components, then compare voltage of returning signal to computer. It could be that a particular wire is part of a reference signal group that needs to be in place. So leaving all and testing operations might be safest, then hack and whack when you're absolutely sure something isn't needed. A good schematic of your wiring should help you decide too.

Nice Swap!
 

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I would advise against cutting anything off of the harness just for the sake of getting rid of it. By using what you need and leaving the rest of the harness intact, it would still be possible to return the vehicle to it's original configuration should the need arise. Also, with the OEM terminal covers in place, there is less likelihood of a wire or wires shorting together, to power, or ground. Unless, of course, you take the time to heat shrink every one the terminated wire ends, which I would classify as being labor intensive, to say the least. Last, but not least, there is the possibility of eliminating something that may not seem necessary now but actually is. No need to make additional work for yourself. On my 1990 K1500, I put the unused portion of the harness against the firewall to the left of and slightly below the relay center and wrapped it with a heat reflective sleeve and tape. Unless you're looking for it and know what you're looking for, you would not notice it. I reconnected all the ground wires from the OEM harness and left the ECM powered up, although it now serves no purpose. Clipping the brown and white wire at ECM terminal A5 took care of the SES light. Another option would be to disassemble the instrument cluster and remove the bulb - the ECM is much easier to access.
 
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