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Old Mar 20, 2008 | 04:52 PM
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Default Harness alteration questions

Ok, so I've read the FAQ and printed the schematic and list of what the wires are from there.

If I'm reading this correct I add some relays and a fuse panel to the stock harness? Where can I get a fuse block?

Looks to need 6 fuses.

Other than that I just start removing the wires listed as having been removed and wire the remaining ones to the fuse block and relays and showed correct?

This might be more difficult than I anticipated. Or maybe I'm just not clear on how to go about actually doing the modification...
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Old Mar 20, 2008 | 05:49 PM
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oh and how do you know which way the numbers start on the red and blue plugs? like...say looking head on into it how should it be positioned so the numbers match the pins?
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Old Mar 20, 2008 | 05:59 PM
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Originally Posted by thunderstruck507
oh and how do you know which way the numbers start on the red and blue plugs? like...say looking head on into it how should it be positioned so the numbers match the pins?
The plugs have numbers on them. They are kind of small, but you'll see them if you look.
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Old Mar 20, 2008 | 06:02 PM
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thanks I appreciate it
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Old Mar 20, 2008 | 07:25 PM
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well I removed the pins from the red and blue ecm plugs that were specified and taped them up together

I feel kinda dumb but I really am having trouble figuring out what I'm supposed to be doing with the schematic...

do I splice the relays/fuses in between the ecm plug and the corresponding F body specific (c100 ect) plugs? thats the best guess I can figure out from just looking at the schematic and the fact it was not designated to remove the wires for those from the ECM plugs

am I on the right track here?
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Old Mar 20, 2008 | 09:17 PM
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fuses go between power supply and PCM, relays go between ECM control output and system...
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Old Mar 20, 2008 | 10:07 PM
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Yep, you can add some relays and a fuse panel to the stock harness. You can source them from another car or from the aftermarket. I pulled my fuse/relay center out of a 96 v6 camaro because it had 8 relays and 12 fuses all in one package.

The fuses and relays go between the power supply and the harness. Normally you supply power to the harness plugs (c100, etc).
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Old Mar 20, 2008 | 10:48 PM
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so it's like I was thinking then

I buy some wire to run from the battery to the fuse block/relay, then from the other side of the fuse block/relay I strip part of the factory harness and solder the new wire on to provide power? The only reason I was curious if this was correct is that I didn't know if jumping power to the harness like that would damage the ecm...

Bleh it sounds like I'm over complicating this huh?
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Old Mar 20, 2008 | 11:51 PM
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How big of a hurry are you in to complete the harness? If you can wait until next weekend (sunday), bring it to my house and I'll help you. It's about a 2 hour drive for you, if you are in Fayetteville. We can do the harness in 3 or 4 hours total.
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Old Mar 21, 2008 | 11:51 AM
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You don't need to "modify" an LS1 harness at all unless you want to clean out the unused wires. All you need to do is make an adapter harness for it to plug into. The fuses and relays are part of the adapter harness. In the picture below, see the three connectors on the left side. One side of those is the original LS1 harness, the other side is my adapter harness that runs to the fuses and relays at the top of the pic. The fuses and relays connect to the battery, fans, fuel pump, ignition switch, etc too. Fuse blocks came from AutoZone, and I got a good deal on the relays on EBay. Info on how I did mine is at http://www.blown.net/ls1swap/rodders...1t56wiring.doc.


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Old Mar 21, 2008 | 01:30 PM
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This relays on EBay you are talking about, do they work fine ?
And can you send me the link for these
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Old Mar 21, 2008 | 10:30 PM
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Oh, so I think I understand now...the C100 ect plugs are plugs that would be left over if I were to connect the harness to the engine. So instead of plicing into those wires I'll be building an add on harness that plugs into those plugs.

I already have electric fans, one is a painless kit with a temp sensor that goes into the engine for auto turn on, the other is on a toggle switch under the dash. So I guess I don't even need bother with the hassle of wiring them into the computer.

A/C I'm not concerned with at this point as my car's system needs work.
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Old Mar 22, 2008 | 03:33 AM
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Originally Posted by Rubberduck
This relays on EBay you are talking about, do they work fine ?
And can you send me the link for these
http://cgi.ebay.com/ebaymotors/10-Bo...QQcmdZViewItem
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Old Mar 22, 2008 | 11:52 AM
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The ones I bought were real Bosch brand relays. I wouldn't cheap out on generics. I don't see anyone selling real Bosh stuff right now ebay.

Actually if I were to do this over, I'd go grab the relay/fuse box out of a late model GM car or truck in a junkyard.
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Old Mar 24, 2008 | 08:06 AM
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good stuff right there rodder, you can bet I added that link to my Favorite's.
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Old Mar 24, 2008 | 02:11 PM
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Tnx man
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Old Mar 24, 2008 | 03:09 PM
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I used this fuse block:

http://order.waytekwire.com/IMAGES/M...og/220_077.PDF

It uses the same terminals as the stock fuse block so you don't need to cut any wires. I also used one of the 46095 relays for the main relay and a couple of bosch relays for the fuel pump and fans:

http://order.waytekwire.com/IMAGES/M...og/220_079.PDF
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