Where do I feed the main 12V battery power to wake up the factory interior fuse block when the stock engine harness is gone after an LS swap?
Here is what the documentation says. Each point links to its source; details depend on your exact computer, harness and transmission.
- E38 ECM; Chevrolet Performance NA LS control kit 19171935; LS2/LS3/LS376/LS7/LSX454; 58x/4x; 2006+: Minimum 8-gauge wire for the fuse-block battery stud. (Chevrolet Performance)
- E67 ECM; Chevrolet Performance LSA E-Rod control system 19299067; LSA: LSA fuse/relay center has 50-amp fused accessory studs. (Chevrolet Performance)
- 0411 PCM (GM service #9354896 or 12200411); 1999-2007 Vortec DBC (LM4/LM7/LQ4/LQ9/L33/L59); T56 or non-electronic automatic: Two large black ring terminals supply constant battery power. (PSI Conversion)
- E38/E67 ECM; Speartech 58x manual-transmission harness: Speartech orange 12-awg feeds constant 12 V to the ECM, ALDL and fuel-pump relay. (Speartech)
Confirm against the instructions for your exact parts before wiring. More: Harness and power in our tuning guide.
Confidence: medium — sources disagree or are limited; check the sources below.
Community discussion
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Sources
- LS Series Engine Control System Guide — Chevrolet Performance (via Scribd)
- https://es.slideshare.net/slideshow/har-1019-vortec-swap-wiring-harness-instructions-efi-conversion-fro/47382494 — PSI Conversion
- https://www.crateenginedepot.com/pdfs/lsa_e_rod.pdf — Chevrolet Performance
- https://speartech.com/v/vspfiles/instructions/58xman.pdf — Speartech