'91 OBS wires to keep for LS swap?

[Tiger88]

Hey guys I'm wondering which wires to keep from my '91 obs chevy wiring harness during my 02 5.3/4l60e swap. I've read the altenator, coolant temp, oil pressure..any others?
How do I locate the exact ones I do not need in the old ECU? Is their a Diagram?

Thanks for your help.

[97greenbeast]

get a hold of silverado_lover, he may know

[Blasphemy]

All I can say, is that you've got a lot of thread reading to do and some note taking as well. I spent almost a year researching my swap and lurking all over the forums before I actually started and I've been wrenching my entire life, yet I still have questions unanswered. Your best bet is to gather as many diagrams as possible and start mentally planning what you want out of your swap, like A/C, stock gauges, ABS, etc. I went to the GM dealership and the guy was nice enough to let me pick and choose what diagrams I needed and even printed them out for me. It's best to keep the donor engine's harness as complete as possible so that you have little issue at startup.

[Tiger88]

So Blasphemy, did you figure it out? Is your swap complete?

[Tiger88]

So Blasphemy, did you figure out your swap? Is the swap complete?

[Blasphemy]

The swap is almost complete. I should be firing it up this weekend if all goes well. I forgot to mention that lt1swap.com is my bible when it comes to wiring tips, tricks, and diagrams. I'll be updating my thread "Just another LQ9 swap" when it's up and running.

[Tiger88]

Well my Ls wiring is complete. The computer is flashed. I'm just curious about the stock wires that connect to the new LS computer. Here is the info I have received from Brendan Patton from LT1swap.com:

"The 5.3l will have signals for check engine light, fuel pump relay control. You can tie those into the original wiring. You will want to use the original a/c wiring as well. You should also keep original speed sensor wiring in place, and tie the 5.3l speed sensor to the same wires already going to your speed sensor."