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I am posting this here as well as in the TPI section.
I am trying to gauge interest in a TPI engine harness that is modernized as the title states. By this I mean instead of power distrubtion being at the starter, it is in a fuse center under the hood. In addition, some relays would also be in this fuse center.
I have my old 88 TPI harness to work with and a fuse/relay center from a buick century (IIRC). Both are GM pieces.
I did something similar over the winter with my 88 GTA when I converted to an LS1. I utilized the underhood body harness from a 98-02 4th gen and mated it with my interior harness, ultizing the 4th gen body control module while retaining my digital dash and all of its features and by the same token fixed some of the areas that the factory skimped out on.
I would like to know before I spend the time to build this thing. I would like to point out one thing - for those that inherited a mess of butt splice connectors in their cars - I don't believe in butt splices unless its in the factory service manual - haha
I'm doing the same thing right now with an 02 harness, engine relay bank and body harness. Except I'm running the 02 fuel tank and cutting in the 02 weather pack set-up with ABS. I am going to upgrade the fuel pump wiring to 14ga and split it through the two rear abs channel connector to handle the new current capability the fuel pump will have. How did you handle the rear window defrost?
BTW, I ordered the C100 connectors male/female pins and receptacles to "re-pin" the hole using the 2002 harnesses wires. It's that or I'm going to use the relay bank out of an 04 GTO which is cleaner IMHO it's just a bit longer than what will fit in the drivers battery tray area.
I was tempted to cut out the section for the 02 style fuel/abs connector, but just ended up using the 88 one and grabbed the weatherpack connector off the 88 tank and pinned it onto the 02 tank.
The firewall area I actaully retained the 02 style connector and ditched the old c100. There is more pins in the 02 one and it allowed me to distribute the BAT 1 and BAT 2 (and a whole bunch of other things too) evenly among all the different splices van nuys put into the 88. As far as the firewall itself, the 02 firewall connector is longer, so instead of mating both halves at the firewall, it mates inside the car. I put a plastic grommet harness thing that came with the 02 harness on the firewall and created a plexiglass bracket that holds it in place. You can't see it and holds nicely.
My only problem I ran into was that I had to trim a good portion off the LH highbeam wire because it was green and therefore its a bit short. I have a feeling I will be getting a replacement strand of wire and fishing it out (and replacing) at some point.
My rear defrost was a pain in my ***. First, the lovely bodyshop that did my car, managed to rip the connectors off the glass, being that my car is a notchback, it was a major PITA to reinstall it, due to the glass being the way it is. Along with ripping off the connector, they also managed to rip off a good chunk of the wire that is affixed to the glass. When I fixed it I utilized the 02 defrost wires. (I had a convertible top from an 02 sitting in my attic and grabbed the wires off it) Really if you go to a junkyard or if you don't have a U-pull-it yard by you, then search up ebay or something, you should be able to find it. Many GM cars utilize the same connector.
I am replacing all the loom on my harness with techflex - looks so much better than plastic loom.
I think I will do that for the TPI harness I build
Harness is well under way, and is turning out better than I hoped. So far, cooling fans, maf relays, and fuel pump are in the fuse block/relay box. Next up is ECM, key on to distributor, A/C and more. The mounting spot will be on the drivers side firewall as all the relays there will be removed. The ESC module will still stay there though. As far as positive battery power to the relay box, I think that a new battery cable is best, but if not, then it can be tapped from the alternator or the starter.
The harness out of my '87 IROC was trashed by mice before I purchased the car so I am very interested. The car currently has a 5.7 vortec out of a '98 tahoe in it mated to a rebuilt WC T-5. I am in the the process of installing the Edelbrock vortec tpi base and refinished tpi uppers.
Being that yours is a manual, I can make you a harness similar to the one I am working on, just minus the auto stuff and with manual stuff. Pm me with pics of your harness so I can see the trouble areas, I would rebuild and upgrade yours.
Quick update: harness almost completed and ready for testing. I will be testing most of the circuits on Thursday and will report back here to those that are interested in a harness. Hopefully I will remember to take a video of the harness running the car I am installing it in.
For those interested:
This harness will require no modification to your existing battery cables. I will be supplying a battery cable that will run from the starter to the fuse/relay block. It will be on the same terminal on the starter as the main battery wire. Also, the circuits that will be controlled are as follows:
C100 bulkhead connector:
Pin A4- ignition switch power wire (also feeds most of the interior accessories)
Pin G5- hatch release and lights and a couple other accessories
Starter wire- will be running into a relay in the fuse block- more efficient than running it through the ignition switch and through the gear selector switch.
Ignition coil will now turn on via a relay as well
Alternator will be getting its battery signal via a fuse in the block
Fans will have three relays as opposed to two
MAF relays are transferred into the fuse block
Fuel pump relay is also transferred into the block
Emissions equipment will be getting all power from a second ignition relay in the fuse block
C115- high speed blower motor supply voltage
That's all for now (there is more, I just can't remember off the top of my head)
The harness I have been working on is completed. This harness utilizes all GM/delphi parts. (except for the loom which is techflex. I will supply a schematic which shows exactly what has been changed. This harness is entirely plug and play.
Fuse box which ultizes the following circuits:<br/>ECM power<br/>starting<br/>ignition<br/>charging<br/>emissions<br/>MAF<br/>MAF burnoff<br/>Fuel puimp<br/>fuel pump switch/oil pressure switch<br/><br/>Instead of these things running on a limited amount of circuits, I spread the load out thus if one thing causes a fuse to pop, it wont take out everything else with it, Problems can be narrowed down to one thing. (As opposed to having the ECM/IGN fuse under the dash pop, and not being able to figure outwhat caused it)
Although the diagram will be updated, this is a stock diagram that came with the fuse box. Many of the circuits here have been repurposed for other applications in this harness.
Delphi fusebox
Maf, canister purge and A/C pressure sensor
As opposed to having 7 or 8 wires in the area of the starter, there will be two heavy battery wires, the actual starter engage wire, and the coolant sensor wire for the aux fan and knock sensor wire.
Completely new fan wiring, 3 settings. Also the washer fluid pump connector is there. (completely plug and play) washer stuff was seperate from the light harness. (light harness comes apart at c100
fuse box and battery wire, notice the c100 is lacking the light harness half. If you send me the whole thing I will rebuild it too. As I utlized my ligh harness for my car, you will get just the engine/windshield wiper section of the harness
I originally said that I would sell this harness for around $400, but because I was able to put this together for less, I am going to list it for a lot less. I need to ask a moderator if I can post the price here or if I need to do it in the classifieds. This thread and the one like it in the TPI section was really just a feeler to gauge interest before I invest time and money into it. I wanted the most amount of people to see it, so that way I can get the most amount of feedback.
So, you join 1/2 the C100 harness with the ECM harness. The fuseblock will be near the C100/brake master... Do you have a picture of it in a car? Even just mocked in?
Originally Posted by alex722607
fuse box and battery wire, notice the c100 is lacking the light harness half. If you send me the whole thing I will rebuild it too. As I utlized my ligh harness for my car, you will get just the engine/windshield wiper section of the harness
I will get one and post it by the end of the week. I did have it mocked up in my friends 89 GTA last week, but neglected to take a picture. It was a tight fit with all the stock relays in place so I presume it will fit nicely with those relays removed. Whether the fitnentis bad or good I will post a picture. And in the eventuality that it doesn't fit 100% in that location I did make the harness with this possibility in mind. (It has room in it for movement)
As it happened we ran into snags with the removal of the old harness from the car, so the only thing I have a picture of is the fuseblock/relayblock in its spot. It fits nice and snug and clears the hood. The one modification I have to make is to create a mount for the ESC module on the relay box cover. Its pretty staright forward though.
No problem! Once my friend assembles his car and does a little work to the motor, I will be able to run through all the systems to make sure everything functions as it should. I will post the pictures of course. The only thing that I need to look further into is making sure there is no interference from the hood or the c100 bulkhead connector. He does not have his hood aligned and his hood latch is disconnected, but just from placing the hood down, there was no interference so I don't expect any when the car is assembled.
I am posting this here as well as in the TPI section.
I am trying to gauge interest in a TPI engine harness that is modernized as the title states. By this I mean instead of power distrubtion being at the starter, it is in a fuse center under the hood. In addition, some relays would also be in this fuse center.
I have my old 88 TPI harness to work with and a fuse/relay center from a buick century (IIRC). Both are GM pieces.
I did something similar over the winter with my 88 GTA when I converted to an LS1. I utilized the underhood body harness from a 98-02 4th gen and mated it with my interior harness, ultizing the 4th gen body control module while retaining my digital dash and all of its features and by the same token fixed some of the areas that the factory skimped out on.
I would like to know before I spend the time to build this thing. I would like to point out one thing - for those that inherited a mess of butt splice connectors in their cars - I don't believe in butt splices unless its in the factory service manual - haha
Glad I ran across this post I saw the pictures and briefly read through on the harness u put together and am interested. I am wanting a harness if you still make them. I have a 1992 305 tpi firebird formula.
10-05-2015, 11:49 AM
