Need help merging together wirings of 1990 5.7/350 in cabin with 1998 5.7 vortec eng

Hi everyone,

Some of you are already familiar with my project, to be short it is a Chevy Silverado 1990 step side k1500 5.7/350, with all top end from 1998 5.7/350 vortec (Heads, manifold, MPFI spider injectors, pro comp cam 08-467-8, 0411 PCM from moates with road runner emulator, 4L60E transmission).

So i had long road taken with this project, changing on the way this and that. And lately after installing 4L60E transmission, had trouble of PCM recognizing it, and since i had a scrap wiring, that was cut here and there before i even got it, and had no cruise control working plus to all, and the under hood fuse box cut out, i decided that i get a new used wiring of a 1998 Tahoe, and start merging it together with my in cabin wiring from scrap, so i did get the new used wiring, all completely whole, with no wires cut or damaged with the fuse box, taken of a car to be cut and sold by parts at junk yard.

So i know there are many swaps of engines in trucks like mine to L31 engine, and swaps exactly like mine, but i have searched all of the net, and can`t find any info on merging the two wirings together, the incabit with underhood, via the bulkhead connector C100 and C200 connectors to merge with the 1998 wiring, to have everything functioning, the A/С, Cruise Control, etc...

If anyone has some info, it would be grate, cause for now i have some pinouts for these connectors, but not sure that they are the correct year. And the 1990 schematics are so difficult to follow.

Thanks in advance folks.

Merging wire harness is very challenging!

I've worked with several L31 conversions on the 1986 - 1995 pickups, re-using all the original TBI harness.

For 1986 - 1992 an upgrade to the 16197427 PCM is required.

The next step is to convert the 16197427 computer to MPFI, which mostly consists of rewiring to the L31 injector pod wiring to the TBI injector wiring.

The next wiring modification is to add the 4L60E wiring harness.

Then install a custom PROM chip, and tune as required.

dave w

Hello Dave, thank you for feedback.
As you have noticed, i have repined the L31 vortec engine (underhood) wiring for 0411 PCM, that can control and the vortec injectors and the 4l60e.

You are absolutly right it is challanging, i am braking my brain for this setup, still thinking should i keep the underhood fusebox, i know folks choose to cut it out, to make the wiring more simple and neat. The L31 underhood with 0411, can work by it self, controling everything and the 4L60E, with out the incabin wiring, like most make a bench for L31.
But want to merge everything to work together. I wonder why there is still no rewiring schem or file out in the net yet for this setup, like Lextech has made for the 0411 repining file, it's realy a mistery..

Planning is a good thing when re-wiring.

The option to delete the '0411 fuse block is a solid plan.

The list of old TBI wiring that can be reused:
Fuel Pump Relay wiring.
Battery +
Battery -
Ignition On / Start
Old TBI fuel injector wiring
Old TBI coil power
ALDL Wiring (reconfigured)
Add HO2S wiring
Add MAF Wiring

dave w

Quote:

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Originally Posted by dave w

Planning is a good thing when re-wiring.

The option to delete the '0411 fuse block is a solid plan.

The list of old TBI wiring that can be reused:
Fuel Pump Relay wiring.
Battery +
Battery -
Ignition On / Start
Old TBI fuel injector wiring
Old TBI coil power
ALDL Wiring (reconfigured)
Add HO2S wiring
Add MAF Wiring

dave w

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Thank you Dave.

Ok as i called the thread i have done some homework)), i have made some connector wiring pinout charts for two main connectors i have to merge: The C100 Bulkhead connector & C200 passenger side firewall connector (in 1990 k1500 its called C273 connector, in 1996-1999 C200).

I have obtained a new used untouched wiring of a 1998 Tahoe with fuse-box and everything uncut/untouched, and started looking on how to merge my in cabin wiring with new under-hood, i as well have my old under-hood wiring. And what confuses me is this, the old under-hood wiring was looped with the in cabin wiring, because everything was going from engine to cluster and modules behind cluster & behind the dash and then to the ECM with corrected by modules or cluster signals i guess, not direct. Where as in 1998 vortec the under-hood wiring is hooked up directly to the PCM. So for me to hook up my cluster and all the modules inside the cabin as well as under-hood modules that my old wiring goes to like ABS & Cruise control, how should i pair the wirings Sensors -> new PCM - > Incabin, and if one wire has to go to both, just split it? Or does it have to be sensors -> cluster and in cabin staff -> New PCM.
For example my VSS signal used to go from trans case to C100 Bulkhead -> Cluster -> C273 passenger side -> ECM. I can live that as it is and get the VSS signal to my New PCM from C273 connector, but that will bee a hell of a loop of wires around the cabin, or i can just have the VSS signal go directly to the PCM From the trans case, and then have separately signals go from pcm to speedo etc..

As well i`m a bit confused on how to merge these connectors C100 & C200/C273 together correctly, totally different wires in old vs new C100 & C200/C273 connectors, only a few are coming and going to from to same place in one-another...

Hope my tables will help someone and ease their job.

If someone could suggest me a way out with my headache, i would appreciate, a psychologist will do but only if he has experience in swapping L31 into 1990 L05 truck. :popcorn:

There are several ways to accomplish your wiring goals. A good first step would be to Identify and label the necessary wires. Be careful about wire colors, for example the fuel pump relay wire is usually green with a white stripe just like the AC wire is usually green with a white stripe. Skills reading schematics and skills using an OHM meter is a requirement, not optional.

dave w

Hello Dave, thank you for warning me about colors, i assumed there isn't different color for every connection, all thaw they could have achieved it using shades and stripes like they do. Yes i am marking every wire, to see exactly what it is and where it's leading to, as well to see what i can throw away, like EGR for example, i have it closed with a plate, so no need wiring connection for it.
But still quite confused, on the best way to merge my engine compartment wiring old and new together via C100 & C200/C273 between each other, for best configuration achievement...

https://www.youtube.com/watch?v=d-1do_t2Xmw

https://www.facebook.com/pg/LT1-Swap...70183759682543


dave w

Thank you Dave, I have seen the video, a lot of info, i am as well signed up to the facebook group and have posted my pinout chart their, in case someone will find them useful, but i haven`t seen the pictures and read the comment from the "1999-2002 4.8L, 5.3L, 6.0L Harness Re-Work Step by Step" that you have provided a link to, will study, a lot of helpful info their. Thank you

Hi Dave, i lied, that`s not the video i have seen, this one has all the info i need basically, thank you very much!!!

Few questions:
- Does anyone know how do i wire speedo from 0411 pcm wire that gives 4K output: via VSS Lo or VSS Hi wire, or both toghether?
Because the old type of speedo used to get the signal directly from the VSS sensor and transform it to 4k and then out of speedo to PCM/ECM as 4k pulses. But with the swap, the signal goes direct from sensor to PCM, PCM transforms it to 4k and out of the PCM. So where to wire it in the speedo, to wich wire/s???

- Another question is my VSS sensor is located on my transfer case NP241C, will it function correct with 0411, or will i have to change it if someone knows?

Thanks.

Ok, I found wiring scheme for speed signal DK_GRN wire coming out of C2 pin-50 connector of 0411 PCM.

But my main question is can i wire this DK_GRN wire coming out of C2 pin-50 directly to C100 Bulkhead (VSS Hi -Yellow wire) that used to get direct signal from VSS sensor twisted together with PPL wire Low range signal (that i just ground), and entered through Bulkhead C100 connector -> DRAC -> Speedo, or do i have overpass the DRAC and wire it directly to speedo?

Attachment 13447

Maybe it's possible to split / splice the VSS into two signals (4 wires)? Have two wires to the DRAC / VSSB to operate the Speedometer and have two wires for the '0411 PCM?

The DRAC / VSSB uses 40 Pulses Per Driveshaft Revolutions (PPR). The DRAC sends the speed signal to the speedometer.

The '0411 uses 40 Pulses Per Driveshaft Revolutions (PPR).

dave w

Quote:

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Originally Posted by dave w

Attachment 13447

Maybe it's possible to split / splice the VSS into two signals (4 wires)? Have two wires to the DRAC / VSSB to operate the Speedometer and have two wires for the '0411 PCM?

The DRAC / VSSB uses 40 Pulses Per Driveshaft Revolutions (PPR). The DRAC sends the speed signal to the speedometer.

The '0411 uses 40 Pulses Per Driveshaft Revolutions (PPR).

dave w

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Hello Dave,

Thank you for reply,

Previously, before i got a new 1998 wiring, becouse the first one i got for free was all cut here and their, i tried splicing in in to the vss two screwed together wires ppl/wht&GRN/black, and connecting to Drac, and what happend is the speedo did not work and the 0411 did not see the vss. That is why i`m thinking of a solution, becouse this schem did not work unfortunately....

Got to find other solution, people say to wire the C50 GRN speed out of pcm wire to speedo directly passing the DRAC, but Cruise uses DRAC on older vehicles and abs as well, i wonder if these modules can use the C50 signal out of PCM as well...

If the DRAC sends 4k to Cruise, as the schem you have attached sayes, i can wire the it from C50 0411 speed signal, what wories me is that the speedo it says uses 2k at some vehicles..

Thank you.

Sincerely.

I've successfully split the 4L60E 40 PPR for both a '0411 PCM and Dakota Digital Electronic Cable Drive Speedometer Control Unit ECD-100: http://www.dakotadigital.com/index.c...rod/prd886.htm

Maybe the Dakota Digital SGI-5E will be a solution: http://www.dakotadigital.com/index.c...rod/prd126.htm

Perhaps the SGI-5E has the ability to supply multiple outputs from one single 40 PPR (VSS) input; which would eliminate the need for a DRAC?

Additional information on the SGI-5E http://www.dakotadigital.com/pdf/SGI-5e.pdf




dave w

Thank you Dave,

Yeh i gues with the Dokota Digital SGI-5E, you can 'not splice to the vss wires' but plug them to the Dakota module, and from there everywhere else PCM, Speedo, ABS, Cruise, and set each one at pulses they need. That is an interesting module, can`t say it costs a lot, it doesn't, but i know people manage to connect all that from the C50 0411 PCM pin with speed out signal, i just have to find out how. If i dont manage to, i will surely be using your solution with Dakota module.

Thank you for your help!

The VSS sensor signal should be capable of driving both inputs. I'm thinking you're just seeing a ground issue between the circuits. I'd try connecting only the high side of the VSS to the DRAC. That should be pin 21 on the '0411 to pin C12 on the DRAC picture Dave posted. Both should be ppl/wht wires.

If that doesn't work, then ohmmeter the VSS wires into each module and see which ones are connected to the ground terminals.

The ppm for each signal is listed on the DRAC pictures. Speedometer is 2000ppm, cruise is 4000ppm and the RWAL is 128,000ppm. So, the speedometer would read double and the RWAL would not work if you used the VSS output on the PCM. You could fix the speedometer with a frequency divider circuit, but the RWAL would be lost.

Quote:

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Originally Posted by lionelhutz

The VSS sensor signal should be capable of driving both inputs. I'm thinking you're just seeing a ground issue between the circuits. I'd try connecting only the high side of the VSS to the DRAC. That should be pin 21 on the '0411 to pin C12 on the DRAC picture Dave posted. Both should be ppl/wht wires.

If that doesn't work, then ohmmeter the VSS wires into each module and see which ones are connected to the ground terminals.

The ppm for each signal is listed on the DRAC pictures. Speedometer is 2000ppm, cruise is 4000ppm and the RWAL is 128,000ppm. So, the speedometer would read double and the RWAL would not work if you used the VSS output on the PCM. You could fix the speedometer with a frequency divider circuit, but the RWAL would be lost.

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Hello Lionelhutz,

Thank you for your input, i`m not sure i have the DRAC on my truck, haven`t found it, it seems that I don`t have it.

I was thinking of changing the RWAL module to a full 4 wheel ABS module of the same 1998 Tahoe i got the wiring from, and getting the hubs, sensors, and sensor plates for the front wheels. Then i gues i will be able to use the PCM C50 speed signal to run it...

Before i have paralleled the VSS signal right out from the sensor to PCM and speedo, and unles i dropped one of either of them would work, i will try using just hi side, all thaw, i have to measure, in my 1990 schematics the Hi signal is YEL (not PPL/WHT) and on the 1998 Hi is PPL/WHT, that is where the problem could have been hiding, that is probably the reason the cluster didn`t work in parallel with PCM...

I will try connecting the wiring back to the vehicle this weekend and see if it all works out fine or not, i`d bother splice to connect the speedo at the fender, under the hood, then splicing in under the car at the trans...