94 c1500 wiring help

[dickwiley]

Ive got the 5.3 harness done, now im tryin to hook the ls harness to truck and having issues finding everything i need to hook the ls harness too. Im not good with wiring at all. Pictures diagrams anything would be great. Its a 5.3 dbc with 4l80e.

[Bear]

Hi, I have a 94 also and I just finished my wiring this weekend, so I can help you while it's still fresh in my head. Here's the diagram that I used to trace my wires from my instrument cluster.



I can go in my garage in a little bit and give some pics of where the wires are. The speedo, tach, and SES light are behind the glove box. Your temp and alternator come out of the C100 on the drivers side firewall.

[dickwiley]

I appreciate that a lot you got a number maybe txt would be better just pm me

[Bear]

On the driver's c100 on have the temp wire which is dark green. The alternator wire is brown. And the oil pressure wire is tan.



Here are the labeled wires



Behind the glove box there is the large black and blue connector. This has your tac and SES. Also there is a white connector that plugged into to DRAC. The last two wires on one side of this connector are a blue wire with a black stripe and a red wire with a black stripe. Pull the two wires from the connector and wire them together to your VSS wire from the LS PCM.





Feel free to call me with any questions you have and I will help you as much as I can. I sent you a PM.

[kewljay223]

not to highjack, but tirebite, do you know which wires on the firewall grommet on the passenger side are for the PRND signals? there are 4 of them blk/ yellow white... dont know exactly off the top of my head. i accidentally cut mine without labeling them and there are duplicate colors that are cut going to the gromet. i know the 4 i want are all grounds and go straight to the dash cluster, but im afraid to just start grounding out random wires (to see if the indicator lights) as some of them go to my old pcm which im still using. this is all i have left wiring wise and i dont want to rip apart my dash to trace them back to the grommet if i dont have to...

[Bear]

I would love to help, but I know on my 94 the PRND signal is build into the column. I know in 95, chevy under went a big change. They kept a lot of their wiring the same and it shows still till present day. Being yours is only a year later than mine and I also removed all of the factory wiring, I re-attached two red power wire that came through the firewall to the junction block and everything works except for the brake lights and wipers due to a factory relay that I removed. The PRND info that I acquired came straight from Brendan @ Lt1swap.com. I still have not acquired a C100 pinout for my truck but I was able after hours of playing with a volt meter was able to identify all but 2 wires. I have the pinouts for what goes behind the glove box. It may not be correct for the 95 but it's a starting point. Happy to help in anyway I can. PS congrats on your emissions test..... Cali is no joke. I have been reading your build thread for some time. Very nice. - Bear

[kewljay223]

thanks. im just glad that part is over with. now i can hve some fun with it. anyway, i will just have to hope for some luck and just start grounding them to see which ones make the indicator light up. lol let me know if you find anything. and nice work on the truck so far!

[dickwiley]

The wires ive found for oil is red tan white, water yellow black, alternator brown and tach white but for tach im try to trace the right white wire. And on my stand alone harness it looks like i have. ᤾2 wires for the ses light

[Bear]

Are you using an already made standalone harness or did you do the conversion yourself from a factory harness? What year engine did you acquire for this conversion? The oil, red tan white? Is this on your new harness or on the 94 truck? I am about to be in my garage and will be able to put eyes on my connectors. I can make a diagram of the connector behind the glove box to show exactly what pins you need to connect to.

[dickwiley]

I buddy made the standalone harness and its not vehicle specfic its the lt1swap.com harness so it can go in any vehicle. My engine is a 01 5.3 converted to dbc and 80e swap. Truck had the 350 tbi in it. So now im merging the standalone to the truck harness. So from ls harness its tach check engine vss tcc fuel pump 12v constant and key 12 volt