wiring advice

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Jun 19, 2020
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Location
Iowa
Good day All
As most of you know, I'm currently building a Factory Five Roadster. The link is here ->https://bobistheoilguy.com/forums/threads/project-cobra.391098/

Anyway, I'm looking for some input on the wiring for my car. The kit I purchased came with an aftermarket wire harness, and I think it will work out fine. As noted in my build thread, I have installed the fuse panel and started to route the main harness. I have routed the front harness for the head lights, turn signals and fan wire. One thing I noticed is this wiring kit does not include a ground wire for the front harness. Instead, it has separate wires in the kit that appear to be for individual grounds for each light. I have thought about this, and I am not a fan of separate grounds for the lights. My theory is too many grounds will end up being a problem at some point.

So now my question, does anyone see an issue if I run a wire in the harness that is a ground and then ground it near the fuse panel in the foot box? I would run a common wire in the harness with branches off for each of the lights. I would solder and shrink wrap the connections. I would also do the same thing for the rear harness when the time comes and tie the grounds together into one connection in the footbox area.

Thanks in advance, for any help that is provided
 
I figure the harness people did this for a reason, presumably reliability. I assume this is fiberglass over a space frame? Maybe they don't want you monkeying with the frame, scraping paint off for better grounds, etc.
 
I figure the harness people did this for a reason, presumably reliability. I assume this is fiberglass over a space frame? Maybe they don't want you monkeying with the frame, scraping paint off for better grounds, etc.
It is a fiberglass body over a tube frame. My only rationalization for how they did this is cost. The short pieces of wire are likely cheaper than the long strands in the harness. My main concern is multiple grounds and the issue that creates with troubleshooting if there is an issue. It also introduces multiple points of corrosion on the frame.

In my mind I should have a battery ground, engine ground and harness ground, so 3 in total.
 
Whoops, I read it backwards. Yes it would be a good idea to run a parallel ground for the major amp draws, eg, headlights. Or do a hybrid version where you use the stock harness and grounds at each corner but add a ring connector under the same fastener and wire to daisy-chain off to the next ground position.
 
You could "Bus Bar" the grounds, It's how I like to wire Corvettes. I've used Littelfuse 882-869-7 with good results....It's meant as a positive bus bar & is fused. Just a added layer of protection really. Just need to run the appropriate gauge for the distance & amp load.
 
The ground (return) wires should return to the engine block or battery minus since those are the source of electricity. I would run three main wires: front, center (dash area) and rear then tee all the grounds in those areas into its main wire. You don't have to connect anything to the frame except one connection to the engine or battery minus to drain off static.

The harness for a fiberglass kit car really should have included that as a standard feature. Properly wired trailers and RVs all have a ground wiring network instead of using the frame. Conventionally, the color code of white wire means it is a ground.
 
Higher current drawing loads, like halogen headlights and electric fans, may cause excessive voltage drop if the total wire run is too long (supply length plus ground length) and/or not of adequate cross sectional area. To combat this potential problem manufacturers ground the load close by and use the chassis as the return run. Electrically, the circuit doesn't know how many grounds it has and ground points only become problematic if they induce a high impedance (i.e. due to corrosion, looseness, etc) in the circuit.
 
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