Need wiring help with ls swap

[Ken K]

As you mentioned, you're donor is a 2000 5.3L. LT1Swap.com was already mentioned, but as spoke of, has a ton of info for wiring your "LS" type engine. Your can do it with four fuses and tie into your harness. Yes, locate and re-use your temp and oil sensors for the dash as the donor engine has two locations for temp sensors. Leave the Temp sensor for you engine in place, but go to opposite side cylinder, purchase adaptor kit, install your coolant temp sensor for your truck. The "LS" type engine oil pressure sender is not needed on the older engines, so with the 16m adaptor, your old oil sender will screw right in, just use the OEM wire as the "LS" type, that wire goes into the PCM. Also, Do not use a sealer on the thread as the body of each sensor is ground thru the engine. Only GM's white teflon sealer will work in these cases.
As mentioned above, to make the Tach work, a resistor is sometimes used to create a "Pull-Up" circuit to increase signal strength. Most PCM's generate a 4 cylinder signal, that can be changed during reprogramming if needed.
This can seem hard for someone who has not done a lot of electrical work, much less re-wiring something like this, but there are videos and clear photos & diagrams on LT1swap for that year of engine. Just use solder, shrink tubing and dielectric grease on connectors. Keep the VIN from the donor vehicle and other info as this will help when it comes time to re-program the PCM. That as well, can be done via LT1swap.com. Just note your choices of tires size, differential ratio, A/C or not, Tach signal, Emissions, VATs delete, transmission type, two electrical cooling fans can be enabled thru the new PCM, etc. If you are using an automatic 4L60e that comes with it, the speed sensor is high resolution and goes into the PCM. The PCM uses this info to change shift points.
They make adaptors for different types of speedometers used. I have not check your 2000 donor, but have factory schematics, but newer trucks, share the speed signal to ABS, Radio and speedo on different circuits from the PCM. Yours may vary as I not have info on your truck's systems.

 

[Supercharged111]

OP if you've never done any wiring in your life this will be a real headache. I've done a number of swaps over the years so really wouldn't be that big of a deal for me plus electrons don't scare me. It is overwhelming to the uninitiated, this will be miles from plug and play but, at the same time, it's a very simple thing to do when you stand back and look at it. Just ID every single wire that doesn't plug directly in and find a home for it. I did my first EFI swap in Japan so there's wasn't much info for me. Just ohmed out every single wire and gave them all a purpose.

 

[blacksport]

i found everything with google
but her is pretty much everything you need to know
http://lt1swap.com/wiringharness.htm
when i pulled the stock ecm wires out all i had left was the temp sensor wire that was coming from the dash under the break booster and the oil pressure sensor i ended up giving it power from a switched ing source.and a few wires that went from the harness under the brake booster to under the ac dryer area where the ecm wires come out to the engine i don't know what they do so i put loom on them and left them. i also had to heat up the "square gromlet " theirs like hot glue on them under the plastic
while you are pulling the ecm wires out you will find 2 wires a green and a purple twisted all the way out they goto the new ecm's vss wires mine was pin 20+21 tap into those an the speedo will work
i'm not done making my cruse and rear abs work but they will.

 

[Ls swap c1500]

i found everything with google
but her is pretty much everything you need to know
http://lt1swap.com/wiringharness.htm
when i pulled the stock ecm wires out all i had left was the temp sensor wire that was coming from the dash under the break booster and the oil pressure sensor i ended up giving it power from a switched ing source.and a few wires that went from the harness under the brake booster to under the ac dryer area where the ecm wires come out to the engine i don't know what they do so i put loom on them and left them. i also had to heat up the "square gromlet " theirs like hot glue on them under the plastic
while you are pulling the ecm wires out you will find 2 wires a green and a purple twisted all the way out they goto the new ecm's vss wires mine was pin 20+21 tap into those an the speedo will work
i'm not done making my cruse and rear abs work but they will.

Are u using the stock ls under hood fuse box? Did you do a redesigned wire harness or stay a stock harness? Did you use both computer's or did you do away with the computer behind the glove box?

 

[blacksport]

you don't need the old cpu at all it's in the trash no i didn't used the stock fuse box but you can just use the lt1swap link and get rid of the junk you don't need

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[Ls swap c1500]

you don't need the old cpu at all it's in the trash no i didn't used the stock fuse box but you can just use the lt1swap link and get rid of the junk you don't need

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That is an awesome video. I appreciate that. So all your wiring is coming out of the firewall on drivers side only - correct.

 

[Ls swap c1500]

Does anyone have a detailed wiring diagram of wiring plug in at the firewall on a 93 c1500. I have viewed a few but all looks like Chinese to me lol. Im not a wiring man but im trying to understand it all. Thanks in advance.

 

[Ken K]

I don't have the wiring diagram for your 93 C1500, as they where all on paper service manuals. GM has been using a type of schematics that place each system into cells. Each "Cell" contains the wiring for each component. When someone get you what you need, you will see B+ at the top, wire color and metric size (AGW Equivalent), plus the circuit number. As it progresses down the page, it shows the fuse, connector, component, wire, ground. If a device has solid lines around it, this means the entire device is shown. If dotted lines, this is a part of one portion of the device. You will find that many wire colors and circuit numbers are the same since 1984 when they started this type of schematics. Also, connectors and ground are labeled in two parts. The letter "C" means connector, while "G" means ground. Now, the front is zone 100, Firewall / dash is zone 200. So a connector on the engine, might show C119. This is zone 100, connector 19, same with grounds, like "G100" is main ground on back of head for example.
I had to learn this type of schematic from the old school pages that folded out in the back of the manual onto 6 or more pages. The left was headlights and the last page on the right was taillights. Everything else was in-between.
There are several good "LS" swap on 4 fuses, on youtube as well, many using your square body truck.
Just remove the tape & covering, write & tape each wire using green masking tape for identification later. Get a cheap bag of nylon zip ties to hold harness together to make sure everything works before wrapping up.

 

[Ls swap c1500]

I don't have the wiring diagram for your 93 C1500, as they where all on paper service manuals. GM has been using a type of schematics that place each system into cells. Each "Cell" contains the wiring for each component. When someone get you what you need, you will see B+ at the top, wire color and metric size (AGW Equivalent), plus the circuit number. As it progresses down the page, it shows the fuse, connector, component, wire, ground. If a device has solid lines around it, this means the entire device is shown. If dotted lines, this is a part of one portion of the device. You will find that many wire colors and circuit numbers are the same since 1984 when they started this type of schematics. Also, connectors and ground are labeled in two parts. The letter "C" means connector, while "G" means ground. Now, the front is zone 100, Firewall / dash is zone 200. So a connector on the engine, might show C119. This is zone 100, connector 19, same with grounds, like "G100" is main ground on back of head for example.
I had to learn this type of schematic from the old school pages that folded out in the back of the manual onto 6 or more pages. The left was headlights and the last page on the right was taillights. Everything else was in-between.
There are several good "LS" swap on 4 fuses, on youtube as well, many using your square body truck.
Just remove the tape & covering, write & tape each wire using green masking tape for identification later. Get a cheap bag of nylon zip ties to hold harness together to make sure everything works before wrapping up.

K. I will have to pick up a haynes manual. Thanks.

 

[Ken K]

Find and old mitchells manual, Domestic Truck, Electrical.
Haynes and Chilton's are only good for leveling a short table leg. They are generic at best and do no include any specific electrical wiring schematics. At least the ones I have seen.

Hold on, some one here will get off of work and see your post and scan in what you need, post pictures for your 93 C1500.

You can go to the forums tab, find electrical or just use the search box on the upper right corner.

Even a blind hog finds the corn from time to time.