robbied31

iTrader: (1)

Hello,
The background..... LQ4/4L80E/PCM/Harness from '2000 2500 truck into a 67 Chevelle. I am using the Current Performance fuse/relay box, autometer guages, Lokar shifter w/ nuetral safety switch and a Vintage Air AC kit. I want the PCM to be involved with the AC so fans and idle speed will get adjusted when AC is on.

I have modified the harness removing everything not needed from all the info on this site. I have a few wires left that I am not sure about.....

What do I do with the following wires?

Wires that went from C2 [now removed] to the trans harness...
1] Trans mounted Neutral safety switch - Light Grn
2] Backup light feed - light Grn
3] Starter relay feed coil - purple/white
4] trans mounted neutral safety switch output park/neutral - yellow

Wires that come out of the PCM...
1] Red 50 - Vehicle Speed output 4k - Grn/Wht - Does this go to speedo?
2] Red 49 - Vehicle Speed Output 128K - yellow/black
3] Red 43 - AC Clutch relay control - Grn/wht - Does this go to AC request in the current performance box?
4] Red 11 - Secondary AC Hi Pressure cutout switch
5] Blue 58 & 59 - Serial Data - Do these both go to OBD2 port?

I have no clue [yet] as to how to wire up the AC to allow the PCM to be involved. I have seen the schematic from AllData, but I have a hard time understanding schematics.

I would appreciate any input anyone has.

Thanks

Rob

the_merv

iTrader: (88)

The two Serial Data Wires.. does it give more of a description of what they are?
Pin #58 for the F-bodies is what goes to the OBDII DLC, there is a second Serial Data Wire in the 1999-up Harnesses that goes to the BCM, it is labeled a little differently than the one on Pin #58..that's why I ask.

The two Speed Sensor Outputs go to a Module on the trucks that converts both readings into the Speedo Signal, the 4L80E has two Speed Sensors..who knows for what reason but it does.

I would say that possibly that Starter Relay one has something to do with the Neutral Safety Switch, just a though..

hookemdevils22

iTrader: (12)

you're running the exact setup i am - well, other than the fuse box and ac system, although i plan to run ac in the future. i may pick your brain when i get to that point. that being said...

c2:
1,2,4) you can run your neutral safety and backup lamp from either the lokar device (if it's equipped with reverse switch, which it should be) or the factory wiring. it'd be easier to go through the lokar device and delete those two.

3) this should go to the starter solenoid relay. it is hot in run only, i beileve. i don't think it would be needed as long as you have a wire to do this function (feed the starter relay to start the car).

for the pcm:
1) yes.
2) i think you need it for the trans output signal, but i'm not sure where it goes. and yes, the 4L80e has 'iss' (input speed sensor) and 'vss' (vehicle, or output, speed sensor).
3) that sounds right, but i don't know for sure.
4) can't help ya
5) 58 goes to the obdII port. 59 is for the BCM, delete it.

if you haven't yet, check out l1tswap.com. lots of good stuff on there. and email brendan on there. he's answered a few questions for me.

one question for you - did your obd port have 5 wires going to it? mine did, so i deleted the extra one on pin 14 (i think?). i haven't heard anyone mention this mystery 5th wire before.

robbied31

iTrader: (1)

Thanks for the help guys.
My OBD2 port had 5 wires also. I just pulled the purple wire out and moved the green wire over to pin 2.

So far I believe I am pretty sure about Red 49 & 50 [use 50 for Speedo and I think delete 49]. Also I am going to use Blue 58 for PCM and delete 59.

I am still not sure about the trans wires or how to hookup the AC with the PCM involoved.

Rob