Wiring Disaster

[Jeremy Graulich]

Ok, I have 1998 K1500 recently swapped 5.0 for built 377 Stroker Cam Heads Crankshaft the works and finally got it finished with a coworker on our off time. Bought all the necessary things to make 4l60e shift as I had done plenty of research after being convinced to go carb which is t the issue. My issue is my “friend” really sucks at wiring which I’m not great but he cut back a bunch of stuff after hard wiring the starter and furl
Pump inside to the ignition and surprise it started but wouldn’t shift. Gone through pins at Round plug on transmission and NSS has power. Started wondering if it wasn’t the Ignition switch cause it’s basically in limp mode.

So my thoughts were to go back and aside from unused sensors and injector wiring that’s already gone go back to factory as much as possible. No PRNDL on dash and won’t crank. My real dilemma now is I found several wires like Battery Positive Voltage a Brown and a White wire that were cut and not connected I’ve done continuity on everything else from PCM and need to know which goes to my alternator (brown at plug) also have a always hot Orange that pretty sure went to factory fuel pump not connected. I have located and confirmed most everything else. Wanna make sure I have the basics right before I buy or make it any worse than what he did being impatient. Been almost 2 years now and I really need her to run finally. I feel like I’m just couple wires short of being ready to roll. Please any and all suggestions and advice will be a HUGE help. Feel like I’m going around in circles at this point.

 

[1998_K1500_Sub]

Bought all the necessary things to make 4l60e shift as I had done plenty of research...

... it started but wouldn’t shift.

So my thoughts were to go back and aside from unused sensors and injector wiring that’s already gone go back to factory as much as possible. No PRNDL on dash and won’t crank. My real dilemma now is I found several wires like Battery Positive Voltage a Brown and a White wire that were cut and not connected I’ve done continuity on everything else from PCM and

That sounds like a lot of work. Reading on...

I need to know which goes to my alternator (brown at plug) also have a always hot Orange that pretty sure went to factory fuel pump not connected.

Pull up a schematic in the 1998 GM manuals, they're available here:

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

I have located and confirmed most everything else.

Sounds like you're almost done!

Now, on to the tuning...

Are you planning for an 0411 ECU swap?

 

[Jeremy Graulich]

That sounds like a lot of work. Reading on...

Indeed been such a pain but going from PCM nothings labeled for alternator and before I assume and run it to the Battery Positive Voltage wire which colors match. Wanted to see if anyone knew what it’s labeled as. Got Crankshaft position sensor TPS sensor IC control and others mentioned all confirmed and tagged from computer. He really did a number cutting them too short and haphazardly. SMH

 

[Jeremy Graulich]

That sounds like a lot of work. Reading on...



Pull up a schematic in the 1998 GM manuals, they're available here:

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

Sounds like you're almost done!

Now, on to the tuning...

Are you planning for an 0411 ECU swap?

I probably just need to find a whole harness and start from scratch. PCM is fine and timings perfect brand new everything except battery power steering pump under the hood at this point.

 

[1998_K1500_Sub]

nothings labeled for alternator and before I assume and run it to the Battery Positive Voltage wire which colors match. Wanted to see if anyone knew what it’s labeled as.

The manual is in four volumes. Download all four.

I suggest you start with Volume 1, it probably is named:

1998_GMT-98_CK-1_SERVICE_MANUAL-VOLUME_1_of_4.pdf

Search Volume 1 for "8A - 10 - 0 ELECTRICAL DIAGNOSIS", which is on page 292 of the .pdf file (or thereabouts).

Another section you'll want is in Volume 3, "Engine Controls" for the 5.0 / 5.7L engines. Look for pg. 6-1675 (which is approximately pg. 1691 of the .pdf file) for "Engine Controls Schematics". I've attached some of them for the 5.0/5.7 for your perusal.

 

[Jeremy Graulich]

The manual is in four volumes. Download all four.

I suggest you start with Volume 1.

1998_GMT-98_CK-1_SERVICE_MANUAL-VOLUME_1_of_4.pdf

Search Volume 1 for "8A - 10 - 0 ELECTRICAL DIAGNOSIS", which is on page 292 of the .pdf file (or thereabouts).

Another section you'll want is in Volume 3, "Engine Controls" for the 5.0 / 5.7L engines. Look for pg. 6-1675 (which is approximately pg. 1691 of the .pdf file) for "Engine Controls Schematics". I've attached some of them for the 5.0/5.7 for your perusal.

Thanks I’m going through it now! Much more detailed

 

[Caman96]

I feel like I’m just couple wires short of being ready to roll.

I like the ring of that! Lol

 

[Erik the Awful]

There's a ground on the harness at the front of the motor on the passenger side. If you don't connect that ground it won't crank. Ask me how I know.

 

[revmatcher]

Yeah, that ground on the front of the motor with the big wire on it is kind of important. Like, it carries the huge starter current back to the battery. You really, really need that. There are other grounds on the motor, but the starter current is very high and needs this big ground wire, otherwise you push huge current through very small wires. Could destroy stuff or start a fire.