Bypassing starter relay and fuse on LS1
Thread Starter
On The Tree
Joined: Jul 2003
Posts: 117
Likes: 0
Bypassing starter relay and fuse on LS1 Is it possible to bypass the starter relay on an LS1? I was contemplating leaving out the fuse and relay for the starter and just connecting the starter like it originally worked on my '86 Z28. The purple wire from the starter goes to the clutch pedal switch and the yellow wire goes to the clutch pedal switch, then when you push the clutch in, the car is able to start. My only concern is that, from looking at the wiring diagram, there seems to be a ppl/wht wire that comes off the starter fuse that splits off and goes to the PCM from the C101 connector. I'm not sure what this is doing and I can't find it on the PCM pinouts 
. I'm fairly sure that I traced that wire to the C101 connector and that is where it stopped; it didn't continue to the pcm or the engine harness. Anyone care to help me out with this one? I just want to be sure I'm not leaving out something important. Thanks.
. I'm fairly sure that I traced that wire to the C101 connector and that is where it stopped; it didn't continue to the pcm or the engine harness. Anyone care to help me out with this one? I just want to be sure I'm not leaving out something important. Thanks. 
TECH Enthusiast
Joined: Jan 2003
Posts: 634
Likes: 0
From: VA
Its for VATS. This keeps your car from starting if you have the wrong key. I believe you can edit vats out. If so, i dont see why your idea wouldnt work. If you cant edit vats out you will need a vats bypass module. Run the pedal switch to pcm and ignition through the bypass.
I didn't even use the LS1 relay set, did what you're talking about instead and it works fine on my '82 3rd gen.
The purple wire on my '82 C100 chassis connector (drv side firewall below the relay bracket) comes straight off the ignition switch, wires in series with the clutch pedal switch (currently this is spliced together on mine), then hits this C100 connector. I picked up that wire and extended it to the LS1 single-pin connector near the LS1's C100/C101/C105 connector trio. Turned the key, started right up.
I got GM Metri-Pak 630 male pins (needed for the 3rd gen C100 hood, engine compartment side) at the local NAPA. Friendly GM dealer service depts will usually give one or two from their shop terminal kit also.
The purple wire on my '82 C100 chassis connector (drv side firewall below the relay bracket) comes straight off the ignition switch, wires in series with the clutch pedal switch (currently this is spliced together on mine), then hits this C100 connector. I picked up that wire and extended it to the LS1 single-pin connector near the LS1's C100/C101/C105 connector trio. Turned the key, started right up.
I got GM Metri-Pak 630 male pins (needed for the 3rd gen C100 hood, engine compartment side) at the local NAPA. Friendly GM dealer service depts will usually give one or two from their shop terminal kit also.
Thread Starter
On The Tree
Joined: Jul 2003
Posts: 117
Likes: 0
Originally Posted by crainholio
I didn't even use the LS1 relay set, did what you're talking about instead and it works fine on my '82 3rd gen.
The purple wire on my '82 C100 chassis connector (drv side firewall below the relay bracket) comes straight off the ignition switch, wires in series with the clutch pedal switch (currently this is spliced together on mine), then hits this C100 connector. I picked up that wire and extended it to the LS1 single-pin connector near the LS1's C100/C101/C105 connector trio. Turned the key, started right up.
I got GM Metri-Pak 630 male pins (needed for the 3rd gen C100 hood, engine compartment side) at the local NAPA. Friendly GM dealer service depts will usually give one or two from their shop terminal kit also.
The purple wire on my '82 C100 chassis connector (drv side firewall below the relay bracket) comes straight off the ignition switch, wires in series with the clutch pedal switch (currently this is spliced together on mine), then hits this C100 connector. I picked up that wire and extended it to the LS1 single-pin connector near the LS1's C100/C101/C105 connector trio. Turned the key, started right up.
I got GM Metri-Pak 630 male pins (needed for the 3rd gen C100 hood, engine compartment side) at the local NAPA. Friendly GM dealer service depts will usually give one or two from their shop terminal kit also.
Originally Posted by bad86z28
Alright, so what you did was take the purple wire coming off the connector on the firewall and extended it to meet up with the purple wire from the LS1's engine harness. Which then goes to the starter. Is this correct? Just want to make sure I understand you.
I snagged a '99 chassis harness from the junkyard, had all the LS1 connectors and plenty of wire I could reuse...made fabricating a harness to connect the LS1 engine harness to the '82 chassis harness very easy and zero cutting or modification of the LS1 engine harness. A few pics of the harness in progress, just enough to test-start the engine are at:
http://www.warpten.com/carpics/ls1/DSC00033.JPG
http://www.warpten.com/carpics/ls1/DSC00034.JPG
http://www.warpten.com/carpics/ls1/DSC00035.JPG
http://www.warpten.com/carpics/ls1/DSC00036.JPG
Thread Starter
On The Tree
Joined: Jul 2003
Posts: 117
Likes: 0
That's pretty much how I have it hooked up, except, I just used the existing purple wire and ditched the one from the LS1 engine harness. I figure its better to be sure it works before-hand, than have to go back and find out why my engine won't start. Thanks for the help.
