Z48LT-1 Posted May 7, 2007 Share Posted May 7, 2007 Hey all, first of all thanks for all the great info. Just donated some dough to show my appreciation. I'm installing a '95 Caprice LT1 and 4L60E in a '48 Chevy street rod and would appreciate some basic info about modifying the wiring harness. I've got the complete Caprice harness which places the PCM at the driver's side front of the engine compartment. I'd like to hide the PCM on the cockpit side of the firewall so will have to extend many wires and shorten many others. Are there any tools that will help, i.e. to remove/install the pins in the PCM connectors? One of the four connectors is damaged and should be replaced; anyone know any web sources for such hardware? I'll be getting TunerCat and a data logging program, probably DataMaster, and an initial mail order tune. Engine mods will be minimal to start, but I'm deleting the emissions stuff as much to clean up the engine as anything. Any and all advice greatly appreciated. Thanks in advance. Cheers -- Gary Quote Link to comment Share on other sites More sharing options...
Tx1021 Posted May 8, 2007 Share Posted May 8, 2007 Hey man, not sure if this will help you at all but its a pretty decent site with a few links to parts sources. http://shbox.com/1/4th_gen_tech1.html Quote Link to comment Share on other sites More sharing options...
deja Posted May 8, 2007 Share Posted May 8, 2007 Hey all, first of all thanks for all the great info. Just donated some dough to show my appreciation. I'm installing a '95 Caprice LT1 and 4L60E in a '48 Chevy street rod and would appreciate some basic info about modifying the wiring harness. I've got the complete Caprice harness which places the PCM at the driver's side front of the engine compartment. I'd like to hide the PCM on the cockpit side of the firewall so will have to extend many wires and shorten many others. Are there any tools that will help, i.e. to remove/install the pins in the PCM connectors? One of the four connectors is damaged and should be replaced; anyone know any web sources for such hardware? I'll be getting TunerCat and a data logging program, probably DataMaster, and an initial mail order tune. Engine mods will be minimal to start, but I'm deleting the emissions stuff as much to clean up the engine as anything. Any and all advice greatly appreciated. Thanks in advance. Cheers -- Gary You may have to go to your Chevy dealer to get the connector. The factory shop manual has a list of the connector numbers, sorry I don't have my manual here right now. As far as shortening and extending wires I just cut and spliced. Use solder and heat shrink and don't do all the wire in the same location on the cable or you'll end up with a very thick cable. Quote Link to comment Share on other sites More sharing options...
Z48LT-1 Posted May 8, 2007 Author Share Posted May 8, 2007 I should mention I've got the GM shop manual (all three volumes) for the '95 Caprice, as well as a CD of the wiring diagrams for the '95 Camaro (I've got a Camaro instrument cluster I'll be using) so I should be able to figure out where all the wires go, but I was just wondering about the mechanics of modding the harness. I anticipated splicing wires and using both solder and heat shrink. Did you just snip off the unused wires or go to the trouble of removing the pins from the connectors? Oh, yeah, I've also got an '01 Z-28 fuel tank with sender and pump I hope to use, using the comprehensive instructions provided by others here. Cheers -- Gary Quote Link to comment Share on other sites More sharing options...
deja Posted May 8, 2007 Share Posted May 8, 2007 I should mention I've got the GM shop manual (all three volumes) for the '95 Caprice, as well as a CD of the wiring diagrams for the '95 Camaro (I've got a Camaro instrument cluster I'll be using) so I should be able to figure out where all the wires go, but I was just wondering about the mechanics of modding the harness. I anticipated splicing wires and using both solder and heat shrink. Did you just snip off the unused wires or go to the trouble of removing the pins from the connectors? Oh, yeah, I've also got an '01 Z-28 fuel tank with sender and pump I hope to use, using the comprehensive instructions provided by others here. Cheers -- Gary Personally I just cut the wires and either shorten or lengthen them one at a time so you don't get confused. I basically do this for a living (computer engineering tech) and finding the correct pins to crimp on the wires is bad enough, but the crimp tool will cost a small fortune if you can even find one. Your standard AMP super champ crimper is not going to do the job. I'm using the entire Z28 wiring harness in my car (insane I know) and so far I only have one unused wire going to the ECU. I will leave about 6" of the wire, put some heat shrink over the end and wrap it into the harness, just in case I ever need it, I think it came from the ABS or the traction control, don't remember right now. It’s a brown wire at the corner of one of the ECU connectors if memory serves me. I used the '94 Z28 metal tank from my donor car. The '01 is no doubt a better choice but since I had this one and it was in perfect shape I decided to use it. BTW if you need the connector and pigtail for that Camaro gauge cluster I will have one. I am converting over to Firebird gauges cluster because I think it looks and fit better in my dash plan. But of course the Camaro and Firebird use different connectors!!!!! This is assuming I can find a GM # 12065803 connector, probably have to go to a dealer. There are pinouts for the Camaro gauge cluster at http://shbox.com/1/95_z_cluster_pinout.jpg But it doesn't look complete. If you need that I can get it from my Camaro manual. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 8, 2007 Share Posted May 8, 2007 I removed the pins from the connectors, once you take one of those connectors apart you'll realise there is no need for a special tool. Wheelman Quote Link to comment Share on other sites More sharing options...
gvincent Posted May 8, 2007 Share Posted May 8, 2007 Deja, I am just getting started on my LT1/T56 project, I have a 95 Trans Am that I will be stripping in the next couple of weeks, If the instrument harness is something you need and something I don't need I will give it to you. I do not plan on using the Trans Am dasboard, I only want to use my stock 76 280Z gauges and maybe a couple of aftermarket gauges on a pillar pod. I currently have the stock 280Z FI harness completely removed and have removed the complete front harness, I have the JTR book but am not 100% sure what of the many wires to remove and incorporate into the LT1 harness yet. There are so many factory splices in the 76 280Z harness that I am totally confused at the moment. So I have the 280Z harness all tagged and set aside for now putting off the wiring for the moment while I prep the engine bay and pull the LT1/T56. Thanks, Greg Quote Link to comment Share on other sites More sharing options...
deja Posted May 8, 2007 Share Posted May 8, 2007 I removed the pins from the connectors, once you take one of those connectors apart you'll realise there is no need for a special tool. Wheelman Not to remove the pin from the connector, but to chrimp on a new one??? Quote Link to comment Share on other sites More sharing options...
Guest 72240Z Posted May 8, 2007 Share Posted May 8, 2007 Try this site http://www.eficonnection.com/eficonnection/100w.aspx Quote Link to comment Share on other sites More sharing options...
deja Posted May 8, 2007 Share Posted May 8, 2007 Try this site http://www.eficonnection.com/eficonnection/100w.aspx Thats a good site. Those connectors are for the LSX not the LT1 but the pins may be the same. $80 for the crimper! Lots of other good connnectors on the site, bookmarked, thanks. Quote Link to comment Share on other sites More sharing options...
piston Posted May 11, 2007 Share Posted May 11, 2007 wow, for a second, i thought you was my buddy here in town. hes got a 54 chevy, dont know what the heck it is, im wiring his lt1 into his chevy for him, if your using aftermarket gauges, itll be alot more simple. obviously, you will need to, since the 1948 gauges im sure will not work with the lt1. you will find alot of good info on here if you search under my old threads, i have the same setup your looking for and all the info is on here somehwere. but let me do some homework for you since im not busy... for the clip/connector for the pcm, pull the red clip and push on the side of the color cover, slide the color cover off, the pins will slide out, pull the ones you dont need, and it looks soo much cleaner then cutting it. search for ( lt1 delete recap) ...this is the main thread that im sure gets everyone through the wiring. thanks to whoever started it, it helped me out over and over and over, and i still use it til this very day. to extend the caprice harness to go back into the cockpit firewall seems like itll be a alot of work, keep an eye out because you wouldnt want to mess up the wiring and open up the wire looms over and over and over in the future to find out some wires are not there. take out everything you dont need and keep the basic wires. just do alot of thinking ahead of time before you delete them out. the 1954 chevy, lucky him, his engine came with a painless, but it looks like hell compare to my caprice harness. everything is delete like power steering and a/c and emissions. you will see that the harness gets smaller and smaller, but it thats al it really takes to run the lt1. gvincent, on the 280z fi harness, its simple...just keep the light wires connected, if engine is pulled already, just mark the oil/amp.water temp and basic wires you want to run with the lt1. everything else thats connected to the engine, just pull off, mark the alternator and big white w/red strips. that will go to the fusebox or positive constant hot power supply. pretty much, the jtr covers the wires you will be needing. instead of how its wired to the carb engine, convert it to the lt1 and it will fall into place. it takes time, i did mine out of the blue pulling it all off within couple hours, the only thing in my stock harness is controlling the lights around the vehicle and factory 3 middle gauges. Quote Link to comment Share on other sites More sharing options...
Z48LT-1 Posted May 11, 2007 Author Share Posted May 11, 2007 Piston, I thought I had found all the LT1 wiring harness posts on the site but your mention of the lt1 wiring delete recap sent me back to re-search and re-read everything and the one thing I did find was some broken links entitled "lt1 wiring delete". Anybody have a copy of this thread which has apparently gone missing? Actually I'm not sure I'm all that concerned about what to delete, exactly, because I'm pretty sure I can noodle through what I won't be using. Regarding gauges, I got a '95 Camaro Z-28 instrument cluster off of ebay and was hoping that I would be able to duplicate the relevant wires to solve all those problems. (Crossing my fingers that the fuel level sensor in the '01 Z-28 fuel tank I've got has the same electrical characteristics as the one in the '95 tank...) (Also that the Caprice PCM has the same signal as the Camaro PCM for things such as tachometer input, etc.) Deja, the cluster I got happened to have the connector and pigtails so I think I'll be able to wire it up OK but I'm also hoping to use the lighting controls as well as the a/c controls from the Z-28 (also off ebay, natch) and neither of those came with any pigtails so if you (or anyone else reading this far) have any of those I'm definitely interested. Likewise for some of the other engine compartment connectors aside from the PCM connectors, although I my choose to simply hard-wire most things to clean up the engine compartment. Anyway, thanks for the advice, everybody; I think I've got enough to get my self thoroughly in trouble now. Cheers, and thanks also for indulging my non-Nissan issues! -- Gary Quote Link to comment Share on other sites More sharing options...
deja Posted May 11, 2007 Share Posted May 11, 2007 Deja, the cluster I got happened to have the connector and pigtails so I think I'll be able to wire it up OK but I'm also hoping to use the lighting controls as well as the a/c controls from the Z-28 (also off ebay, natch) and neither of those came with any pigtails so if you (or anyone else reading this far) have any of those I'm definitely interested. Likewise for some of the other engine compartment connectors aside from the PCM connectors, although I my choose to simply hard-wire most things to clean up the engine compartment. Sorry, I am using the light control so I need that pigtail and I already gave away the AC control with all the vacuum control lines. Quote Link to comment Share on other sites More sharing options...
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