Project "Tow"

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07-21-2009, 08:09 PM
SpecV44

Project "Tow"

I should have started this thread before I started the swap, but I guess I can start it down since I havent really gotten too far.

The truck is a 1994 GMC 1500 ext cab, the odometer says ~250k, but the truck itself is pretty straight, and most importantly NO RUST.

http://i34.photobucket.com/albums/d1...100_1492-1.jpg

http://i34.photobucket.com/albums/d1...100_1493-1.jpg

http://i34.photobucket.com/albums/d1...100_1494-1.jpg

I originally pulled the 5.0/4L60E out and put my 360ci/4L60 combo in so I could use the truck, but that didnt last long as that Holley 750 didnt make for very good gas mileage.

I drove to tampa one weekend to pull the 5.3/4l60e from a 2002 silverado. The motor/trans have just under 100k on them, and for the price I couldnt beat it. For $800 I got:

5.3 iron block/aluminum heads
4L60E
all accessories/brackets
radiator
fan shroud
full a/c system
y-pipe/manifolds
all sensors
every inch of wiring under the hood, all the way past the fuel tank
ecu/OBDII port
full air intake/air box
a/c condensor

I used Trans-dapt motor plates, to bolt SB1 mounts on to, but they didnt work very well. I dont know if the trucks need different plates or mounts or what, but the stock truck mounts didnt work correctly. I bolted them to the plates and tried to set the motor in place, but it wouldnt sit right. I could put 1 bolt in the mount on the frame, but when I would try to put the other bolt in, the hole was 1/2" off. So rather than try to figure it out I decided to build my own frame mounts. The welds kind of look like hell, but it is all solid and reinforced with 1/4" plate steel so I know they arent going to collapse.

I notched the frame for the a/c compressor, filled it back in with 16ga sheet steel, which apparently is just on the edge of too thin to weld with my arc welder. I put the motor back in and the compressor has room front to back, but it is just barely touching on the outside of the compressor, so I will have to revisit the notch when I pull the motor back out.

http://i34.photobucket.com/albums/d1.../acnotch-1.jpg

7/22/2009

Tonight I finished pulling all the wiring from the old ECU, which was pretty simple. Behind the glove box is the ECU. Unplug the 2 connectors attached to the ECU, the 1 big black/blue connector, and the small black 3 wire connector (A/C-heater stuff I believe). After you unhook that, you can pull the wires out from behind the dash, underneath to the floor. Under the hood, you will see on the passenger's side where the wires exit the cab and enter the engine bay. There are 2 7mm screws holding the black weather-proofing box to the firewall, I found it easiest to remove the coolant overflow tank to get to it. The coolant overflow tank is held on by 2x 13mm bolts on the top, then pull up to slide it off the firewall.

http://i34.photobucket.com/albums/d1...ntrancecab.jpg

After you pull the wires through the firewall to the engine bay, you should be able to pull all the wiring/connectors over to the driver's side, where they end (go back into the cab to meet the fuse box). The weather-proof box is VERY difficult to get apart, as GM decided to GLUE the wires to the wire holders in the box, then at the same time, glue the wire holders to the box itself. I wish I knew where my torch was while trying to get the box open. Regardless, it took about 10 minutes, but I was able to pry the box open to get a look at the wires. At this point, I was able to find my torch and started heating the glue to release the wires. You have to be careful here, as you dont want to burn the wires or melt the box. I held the box so the glue was vertical, and could run off the bottom as it melted. I heated it for about 10 minutes, then while the glue was hot I started pulling wires out. I suggest having your wires cut off the connectors (ECU) before starting this, so you can pull as many as you can before the glue gets cold. Depending on how much of the glue you let run off before cooling, you will still be able to pull wires after it has cooled, which is what I was able to do.

In the end, I was left with about 10 wires, which were for the alt (gauge wire), A/C front and rear plugs (compressor), oil pressure (gauge), wiper motor, purple starter wire (solenoid, column) and I believe that is it.

http://i34.photobucket.com/albums/d1...overwiring.jpg
http://i34.photobucket.com/albums/d1...ningwiring.jpg

Random pics

Clearance

http://i34.photobucket.com/albums/d1.../clearance.jpg

Engine

http://i34.photobucket.com/albums/d1...500/engine.jpg

Reworked harness

http://i34.photobucket.com/albums/d1...500/wiring.jpg

7/28/09

After work tonight I started on a little bit of stuff. I got the transmission crossmember put up, still need to get a bigger drillbit and the correct bolts to oblong the crossmember holes, since of course after welding everything down things dont fit exactly as they should lol.

Also routed the crank pickup wires, 12v to the starter, solenoid wire, a/c wires underneath to the hookups.

After I did that, i wanted to check fitment of the 2002 Silverado radiator, and when I did that I also tested the fan shroud, and air box. A little trimming and the airbox will fit awsome.

Since the airbox on late model Silverados is on the passenger's side, they have the battery on the driver's side behind the headlight. Unfortunately my truck didnt come with the dual battery trays. so after removing the battery tray from the passenger's side, I cleared the driver's side to ensure that it had provisions for the driver's side factory battery box, which it does, minus the holes. I need to swing by the salvage yard and pick one up, or check and see if my shop truck has the same mounting location, as it does have the 2nd battery tray.

There are 2 13mm bolts and 1 13mm nut that holds the driver's side battery tray down.

http://i34.photobucket.com/albums/d1...0/SNC00031.jpg

http://i34.photobucket.com/albums/d1...0/SNC00032.jpg

Here are some pics as it sits now. Tomorrow I will have to do some cutting on the radiator, take the old condensor out, along with the old aux trans cooler then I can start test fitting the aux power steering cooler, aux transmission cooler, condenser, and get the silverado radiator tied down.

http://i34.photobucket.com/albums/d1...0/SNC00033.jpg

http://i34.photobucket.com/albums/d1...0/SNC00034.jpg

http://i34.photobucket.com/albums/d1...SNC00039-1.jpg

http://i34.photobucket.com/albums/d1...0/SNC00035.jpg

http://i34.photobucket.com/albums/d1...0/SNC00036.jpg

http://i34.photobucket.com/albums/d1...SNC00038-1.jpg

http://i34.photobucket.com/albums/d1...SNC00037-1.jpg

Still need to cut the old exhaust out, get the silverado y-pipe welded back together, get bolts to bolt the manifolds on, starter up, tie the battery down, splice 10 wires into the factory truck wiring, pull the bed and install a new pump or gut the stock pump and put in a boost-a-pump. Still have about 2 months before it will be driveable, but it is getting there and I am gonna be super happy with it in the end.
07-21-2009, 08:13 PM
SpecV44

I started pulling the wires off the old ECU, and the only ones that I am keeping are the ones that I dont know if I need. I am keeping all the transmission wiring (for the moment), any of the cruise wiring, and the speed sensor wiring. I have been searching and searching and searching trying to find what wires I need to keep, and what wires I need to ensure that my speedometer works, but I havent been able to find anything yet.

Can anyone help, or is it kind of just "figure it out"?
07-21-2009, 08:38 PM
RedHeartbeat

Here's a good start... LS1 Swap FAQs - LS1TECH
07-21-2009, 09:52 PM
SpecV44

thanks Red, I already modified the engine harness based on the information HERE. That page is specifically for truck motors/harnesses rather than messing with the common LS1 f-body harnesses.

I was looking more towards the truck itself rather than the motor. Like, can I splice in the plug from the 5.3 a/c compressor onto the factory 94 a/c compressor plug and it will be controlled from the controls inside the cab? I can get around pretty much everything except the speedometer atm, and I think I have that figured out. The one thing I have NO idea about is the cruise. Which is why I plan on leaving the transmission wiring, at least for the time being. Luckily I took the cruise box/cable from the 2002 silverado, and it has the same plug as the 94 truck does so maybe that will help some.
07-21-2009, 09:58 PM
GasGuzzler

I have a 2-door Blazer too...
07-21-2009, 10:01 PM
RedHeartbeat

This might help, too... http://www.ls1truck.com/forums/lsx-t...ol-wiring.html
07-22-2009, 08:05 AM
SpecV44

Quote:

Originally Posted by GasGuzzler

I have a 2-door Blazer too...

That Jimmy has a LQ4/4L60E, cam, rockers, pulley, vic jr, edelbrock elbow, 3400 fuddle stall, 8.8 rear, traction bars, 17"/18" 5 spoke vette wheels :dancenana:

Quote:

Originally Posted by RedHeartbeat

This might help, too... http://www.ls1truck.com/forums/lsx-t...ol-wiring.html

Thanks again Red, that was the thread I was looking at the most.
07-22-2009, 10:40 AM
SpecV44

The red circles are the wires I have cut to remove them. I cut them off at the old ECU and am in the process of routing them out of the harness. I havent been able to find the transmission wiring yet, as that diagram only says "electronic transmission". I also wasnt sure about removing the pink/black wire for the EGR solenoid, or the dk green/yellow for the canister, because they tie into other wires. Can i remove them?

http://i34.photobucket.com/albums/d1...00/diagram.jpg
07-22-2009, 11:27 AM
RedHeartbeat

yes, remove them.

The transmission wires are as labeled on your diagram. Your old PCM is pretty useless in this new setup, may be good for speedometer calibration but I don't think you'll need any of it in the truck. I've gutted all the 92 and 93 models that I've converted, used nothing from the PCM and removed it entirely.
07-22-2009, 11:42 AM
SpecV44

So I dont need ANY of the wires? Im just hesitant to take them all out and then find out later that I needed speedo/cruise/a-c wires and they are already gone.

When I said the transmission wires werent labeled, I meant what each wire runs to in the transmission. I see that they are labeled like the other pins (F8, B5, etc) lol.

So it wont be a problem to remove; E15, F16, all the transmission wires (F8, B5, E2, E4, E5, E8, E9, E10, E11, F1, F7, F10)?

What about E15, F16, since they are tied into other circuits? Especially F16, since it is running into the brake switch?

Im sorry for all the questions, but I want to do a complete walk through when all this is done, for future people, so I want to ensure everything is as accurate as possible.
07-22-2009, 11:47 AM
RedHeartbeat

In the four I've done personally I did not need any of that.
07-22-2009, 12:07 PM
SpecV44

Okay cool. So I should be good keeping only cruise and a/c associated wires? No need to keep speedo wires?

I think this may be the last question I need to ask for a bit lol.

If I remove the speed sensor wires, how do I hook up the speedo in the cluster? I think that may be explained in that 1993 wiring link that you posted above though.
07-22-2009, 07:16 PM
SpecV44

my damn laptop isbeing a pita, so this is from my phone.

i pulled all the wires from the ecu connectors. i think i made a mistake though. when i cut the 1 dk grn a/c wire, i followed it snd cut off the line pressure plug. i followed the 2nd wire from the pressure plug and it went to the front plug for the factory a/c compressor.

is the a/c still gonna work? im afraid it is not gonna work. i also screwed up and cut the white cruise wire off at the firewall. is that a problem either?
07-22-2009, 11:34 PM
RedHeartbeat

Not sure about a white wire to the cruise control. I'd have to look at my setup to see how I have my A/C wired but its not going through the PCM. That may be something new in 94 but mine is wired directly from the dash to the compressor.
07-23-2009, 07:34 AM
SpecV44

there are 2 plugs on the compressor, one in the front and one in the rear. I would just hate to find out that I killed the a/c from that 1 wire, and now it is going to take a bunch of work to put it back together and make it work. Really, I dont think it needs but the 1 plug, but I am unsure about that.

E12 and B10 were the 2 wires Im concerned about. I guess I will revisit them at a later time.
07-23-2009, 02:37 PM
RedHeartbeat

Thought you said you had a sanden 1 wire compressor? You may have to keep the stock PCM in the truck to monitor compressor pressures. Haven't ever had to deal with that since both of mine went to a Sanden compressor.
07-23-2009, 02:55 PM
GMCwantsLS1

The plug on the back is a pressure switch that you won't need. So you can supply power to one terminal on the front plug and ground the other one to make the clutch apply.

Quote:

Originally Posted by SpecV44

there are 2 plugs on the compressor, one in the front and one in the rear. I would just hate to find out that I killed the a/c from that 1 wire, and now it is going to take a bunch of work to put it back together and make it work. Really, I dont think it needs but the 1 plug, but I am unsure about that.

E12 and B10 were the 2 wires Im concerned about. I guess I will revisit them at a later time.
07-23-2009, 03:11 PM
SpecV44

Quote:

Originally Posted by RedHeartbeat

Thought you said you had a sanden 1 wire compressor? You may have to keep the stock PCM in the truck to monitor compressor pressures. Haven't ever had to deal with that since both of mine went to a Sanden compressor.

Damn...

No, nothing aftermarket, I notched the frame for the stock a/c compressor to fit...

Quote:

Originally Posted by GMCwantsLS1

The plug on the back is a pressure switch that you won't need. So you can supply power to one terminal on the front plug and ground the other one to make the clutch apply.

Awsome, so as long as I have the front plug then I am good? Thank God! lol
07-24-2009, 09:23 AM
r6z4o6

Don't be scared, start yanking wires!!!The ONLY wires i kept from the 91 is to the tail lights and to the fuel pump.:D
07-24-2009, 10:58 AM
SpecV44

Its all done now lol. Tonight I am going to finish gutting the 2002 fuse box and hopefully start hooking wires up. I need to go pick up some wire, some terminals and hopefully I can get it cranking this weekend. After I do that, I am stuck for 2-4 weeks so I can buy a fuel pump and credits so I can start tuning.
07-28-2009, 10:01 PM
SpecV44

couple more pictures and a little more work done tonight, check the first post.
08-02-2009, 02:31 AM
keniff

wow a good write up. im going witb a custom harness so should i just take everything out and let the new harness power everything? i have a speed sensor on my truck so that means i have an electric speedo?
08-02-2009, 09:57 AM
Chevy-Art

Good job, can't wait to see it done.
08-02-2009, 11:04 PM
SpecV44

Thanks guy's. I didnt have a chance to get any work done this weekend, it is still sitting there needing the engine harness spliced to get power to some wires, but aside from that it is done. The biggest thing is I am waiting on money to get a fuel pump and so I can buy credits for my HP Tuners so I can get into the ECU.

The writeup is kind of out of whack at the moment, but that is because I started it after I had started the swap, I will fill them in when I pull the motor back out to get a broken exhaust manifold bolt out and to clean the frame.

Thanks again!