Deleting chassis harnesses in favor of new relays/switches - Questions...

[SonySlave]

I want to make this clear now, this is NOT another thread about relocating the engine fuse box or removing extra plugs on the engine wiring harness. There are plenty of those threads but very few, if any, threads about the chassis harnesses.

So, my car has always been a bit of an electrical nightmare. Half of my auxilliary gauges don't work (gas and oil pressure) and I barely street drive my car anymore. The car is 98% drag car and I'm tired of having all of the unnecessary wiring in my car. I've determined that I want to eliminate the front and rear chassis harnesses and put only the bare essentials on my own relays and switches, like the headlights, taillights, and radiator/trans cooler fans. I've even considered removing the stock gauge cluster in favor of my own Autometer gauge set.

The issue, as with most people, is that I'm not much of a wiring guy. I've gone through the service manuals and I believe that I know what I want to remove but I'm simply terrified of removing anything for fear of having something else seemingly unrelated stop working. I've already relocated the battery to the rear so the factory alternator wires are gone. I'm going to go through each of the harnesses from the service manual with individual questions:

A Harness (Front Chassis):

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Above, boxed in red, is what I'd like to remove. Essentially, it's the entire harness in front of the motor. I'd like to unplug the harness from the under-dash fuse box and de-pin the other side from the under-hood fuse box. A13-A22 are already gone since I removed the A/C and emission years ago but the empty plugs are just sitting there. Will my plan work without causing issues?


E Harness (Rear Chassis):

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Here, the only things I'm currently using on this harness is the taillights, reverse lights, and brake lights. The fuel pump is re-wired, the stock auto seat belts have been gone for years, and the power windows have always been wonky. I'd love to just unplug this entire harness from the under-dash fuse box and wire the brake and taillights with my own relays and switches. Will I have any issues with this?


D Harness (Stock Gauge Cluster):

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I'm not entirely sure if I want to do this yet, but if I wanted to build my own custom gauge cluster, would I be able to remove this harness (including the gauge cluster) without any issues?


If anyone could answer my questions, I'd be ever so greatful! I don't have the electrical knowledge to understand the circuit diagrams in the service manuals to answer these questions. Thoughts anyone?

 

[Blurred Talon]

If you are scrapping your cluster, you can certainly go with a completely custom harness and ditch the stock one.
You can get a relay/fuse box from Waytek Wire: 30: 1369: Search: fuse box

Waytek and Del City are a great place to get wire, crimps, tools, etc.

A lot of the plugs for lights and the like can be sourced new.

 

[SonySlave]

I know I may be paranoid and making this way harder than it needs to be, but if I remove the A and E harnesses but keep the stock gauge cluster (mostly to keep the CEL functionality for knock awareness from ECMLink), would I cause any issues with the rest of the stock wiring in the car?

I wish I could be more clear. I know that the stock ECU is tied into a lot of the components/systems in the car and components get grounds from several locations and circuits are completed a number of ways. If I just unplug D harness from the back of the under-dash fuse panel, will I cause any issues with the rest of the stock wiring still left in the car? Same with A harness, if I unplug the harness from the under-dash fuse box and de-pin that portion of the harness from the under-hood fuse box, will I cause any issues with the rest of the stock wiring left over?

 

[bryanwheat]

Are you expecting someone to walk you thru this step by step? My best reccomendation is to fix what you have now. If you are not capable of doing that than you are nowhere near capable of building your own harness for this. This may sound blunt, but you have already admitted to being wiring illiterate. This just sounds like it won't end well for you.

 

[DSM_PWR]

I did away with the stock wiring all together and used a brand new wiring board and got it wired from scratch.

Has the bare essentials necessary

Street/Strip Wiring Board

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[92AWDHX40]

Dsm power that's nice, I love that board, oh yeah I love the engine bay, saw it on fb, and here.

 

[Blurred Talon]

I know I may be paranoid and making this way harder than it needs to be, but if I remove the A and E harnesses but keep the stock gauge cluster (mostly to keep the CEL functionality for knock awareness from ECMLink), would I cause any issues with the rest of the stock wiring in the car?

I wish I could be more clear. I know that the stock ECU is tied into a lot of the components/systems in the car and components get grounds from several locations and circuits are completed a number of ways. If I just unplug D harness from the back of the under-dash fuse panel, will I cause any issues with the rest of the stock wiring still left in the car? Same with A harness, if I unplug the harness from the under-dash fuse box and de-pin that portion of the harness from the under-hood fuse box, will I cause any issues with the rest of the stock wiring left over?

Let me look this in deeper detail, I'll comment again.

A lot of the wires on the ECU aren't needed. I spoke with Thomas Dorris when I started my rewire on my car. I was removing things like cooling fan feeds, alternator wiring, etc. The ECU doesn't care about these. All it really cares about is the actual engine related things to make the car run (injectors, power transistor, etc).

I did away with the stock wiring all together and used a brand new wiring board and got it wired from scratch.

Has the bare essentials necessary

Street/Strip Wiring Board

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That's very cool but there's a few things I'd change (not much), that's only cause I'm anal

 

[SonySlave]

Let me look this in deeper detail, I'll comment again.

A lot of the wires on the ECU aren't needed. I spoke with Thomas Dorris when I started my rewire on my car. I was removing things like cooling fan feeds, alternator wiring, etc. The ECU doesn't care about these. All it really cares about is the actual engine related things to make the car run (injectors, power transistor, etc).

That's the kind of response I was looking for. Leaving the ECU and engine harness alone has been the plan all along. Essentially I want to leave the ECU/Engine harness left alone and everything else on the car barebones. While I'd love to have the unnecessary plugs stripped off and a nice relocation of the engine harness done, that's not what I'm wanting right now.

Again, it seems easy based on looking at the diagrams I posted above but the circuit diagrams, which I'm not comfortable with, may tell a different story. I was hoping by doing some of the work by identifying the plugs I wanted to delete on the diagrams that I could get on here and ask some of the wiring gurus to check the circuit diagrams and tell me whether or not it was as simple as I was thinking.