Engine Wiring 101

[TitaniumTT]

Originally Posted by Rotary Evolution

i always prefer a new harness over an old one but the following are steps i use to buy more life from marginal, old, original wiring:

Marginal wiring is a popped engine waiting to happen... would you put marginal gas in your rotary? Why is marginal wiring acceptable?

Originally Posted by Rotary Evolution

convoluted tubing over areas that contact metal where it can rub through the harness or are draped over high heat areas.

I hate convoluted tubing... fucking disgusting shit. First of all, if it's rubbing, secure it. Second, that tubing likes to melt. It doesn't belong in an engine bay.

Originally Posted by Rotary Evolution

most electrical tape you find just about anywhere is garbage. heat, fuel and oil unravel it as the adhesive melts or is compromised by fluids. don't even bother with vinyl electrical tape unless you know it can handle the job, such as an industrial grade wrap. self bonding silicone tape is better for a base insulator under convolute tubing or the actual friction covering.

ALL electrical tape is unsuited for an engine harness.... that is all. PERIOD! If you have a wire that's been compromised, cut it, cut it back, strip it, apply some adhesive lined heat shrink, crimp it, and heat it.

[QUOTE=Rotary Evolution;260337]for actually wrapping the outside of the harness i personally prefer either 3M friction tape or another brand of friction tape which contains more tar. it is self sealing, weather resistant, won't unravel, heat resistant and protects the harness quite well. if it comes in contact with oil or fuel it will get sticky but it won't be compromised.

ALL electrical tape is unsuited for an engine harness.... that is all. PERIOD!
I cannot stand when someone says, hey Bri, what do you think of my wiri..... and I get all pissed off because I see it wrapped with about a 1/2mile of fucking tape... get some damn Raychem or something equivalent... damn...

Originally Posted by Rotary Evolution

if you're going to crimp versus solder, find the self sealing shrink tubes that will reinforce and seal the butt joint.

Good luck bundeling those massive things. Don't forget either, if you use the wrong crimpers you'll slice the massively ginourmous heatshrink and it will just peel back exposing the crimp. I use those in one place and one place only, maring wiring because they are required by the CG, other than that, they are fucking trash... expensive trash to boot.

Originally Posted by Rotary Evolution

the biggest thing about wiring isn't so much the wire but the wire insulation. after years sitting in a 200F engine bay the insulation gets brittle and cracks, exposing the wires where they will begin to fray and oxidize. new wire is always preferred so that you can buy many more years before it begins to do the same. if an insulator is cracked and wires exposed but not compromised you can seal it up with liquid tape to buy a few more years without digging deeper into the harness and repairing it.

Did you really just say seal it with liquid electrical tape? Wow.... don't even know how to respond with that one expect... it's wrong? See above with the cut strip crimp heatshrink.... why Band-Aid something that can actually be repaired properly?

Originally Posted by Rotary Evolution

if you're stripping wiring from an old harness to repair it, hold a lighter under the insulation you're stripping for a few seconds to warm it up and then strip the wire. this helps you strip just the insulator without inadvertently taking half the core wires with it.

Or... OR.... buy the proper stripper? I've never, even with old nasty stock wiring like repining a fucking TPS on the 3rd gen crispy bakes oven engine harness have I broken half the core wires....

Buy the right tools, buy the right crimpers, plan it out, do it once, don't repair shit, there should be zero butt connectors in an engine harness, take all your electrical tape and throw it away when you're building a harness unless you're using it to temporarily bundle wires, Raychem is your friend, spend the money, like levi said though, unless you're planning on doing a few of these, have some different requirements, or just want to take pride in your work, there are better alternatives. I've seen rywires and while they aren't the greatest of fitting harnesses, they use tefzel, they use Raychem, they use adhesive lined heat shrink... I have no idea how they build them as cheap as they do.... for me to do a fully custom engine harness with the bulkhead connector and wire in an ecu and get the car started, you're looking at ~$2k.... but..... at the end of the day, it will last longer than your car and you'll never have to worry about it.

Now.... I'm going to throw feces at a certain green jeep......