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I am posting this here as well as in the electronics 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
there are several factors that need to be taken into account
There are about 4 variations of TPI in our cars.
85 was one off
86-88 was cold start with 165 ecm
89 was no cold start with 165 ecm
90-92 was MAP with 7730 ecm IIRC
Also camaros had batteries on the right and firebird had batteries on the left
as such I only have an 88 TPI drivers side battery harness to work with. It can be adapted to work with passenger side battery, but that is something else, and I would like to adapt this for a drivers side battery, as that is what it came out of
Last edited by alex722607; 10-08-2015 at 10:09 PM.
Correct, LS1 swap harnesses are Pockets thing. The reason I'm doing this is because it is always something I wanted to do to a TPI harness. The life of my SBC engine prevented me from doing so. But my reason is simply that the factory did a ****-poor job
The battery power goes directly to the starter, right?
Then get the main power from there, instead of the battery directly, and then boom, battery location does not matter.
I actually considered that approach. However where the battery sister has an affect on the ECM and relay power fuse. In order to it to be a fully integrated harness, left and right battery position matters.
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
Delphi makes a modular fuse box with multiple bases that fit a variety of fuse/relay combos. Maxis, minis, relays etc in various qtys. Worth a look instead of recycling a massive buick block which will be half unused
What year Buick Century is the relay/fuse center from?
1999-2002 is the same as far as I know. It could also be similar for other years. I chose this one on particular because a lot of the circuitry is built into the fuse/relay box itself.
Delphi makes a modular fuse box with multiple bases that fit a variety of fuse/relay combos. Maxis, minis, relays etc in various qtys. Worth a look instead of recycling a massive buick block which will be half unused
I actually considered this route for the longest time when I was trying to figure out how to modernize/redo this harness. I ended up using this particular block because many power circuits are already inside the box. For example, one of the ignition relays supplies ignition voltage to multiple fuses, without any wires visible on the outside. Its kind of neater I think. The fact that is quite large is something I tried to avoid. Unfortunately the gm fuse boxes are such that if they are not wide, then they are deep and so I tried to work this into the constraints of the third gen.
Thank you for the idea Pocket, I am continuing my quest to find a smaller fuse box to use for the future.
The spots that are unused are mostly fuse spots, most of the relay spots were utilized.
Will do. I haven't worked on the install for testing the harness as of late, but am planning on doing so today. What kind of condition is your harness in?
10-05-2015, 11:50 AM
