LS swap harness questions
Thread Starter
Teching In
Joined: Sep 2014
Posts: 5
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From: Maine
LS swap harness questions Just a few questions about harness re-working. Using an 07 Trailblazer SS harness for an ls swap into an 86 chevy truck. The harness is 95% completed, but I have a few questions about it. The VSS signal has two wires going to the ecu, one green/white pin 39 and the other is yellow/black pin 24, my question here is which one should I use for ecu signal/voltage supply? #2 is the signal for the tach, can I use the white wire labeled for engine speed signal? Thanks in advance!
On The Tree
Joined: Aug 2012
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I'm not sure on the pinouts for that vehicle, but both wires from the VSS go to the PCM, there should be a separate wire for vehicle speed coming from the PCM that's the one you run to your speedo. The Tach signal usually requires a 12vpower wire with a resistor to read accurately. If you haven't already you should look at lt1swap.com there is loads of helpful info there.
Thread Starter
Teching In
Joined: Sep 2014
Posts: 5
Likes: 0
From: Maine
Yeah that's a great site, unfortunately there's not alot of info out there about modifying the e67 ecu and harnesses. Luckily for me, I was able to pull wiring diagrams from ALLDATA. The older harness builds are much easier to re-work, and you don't need a magnifying glass to see the connector pin outs lol
