Wiring harnesses

[befarrer]

Where does everybody with engine swaps run their engine harnesses? Does everybody run it like OEM, and wrap it around the engine?

I am re-doing my Quad 4 harness, and trying something different. I am running the entire harness around the Chassis, and running leads out to the sensors, mine used to go under the intake manifold, then up and over the bellhousing, then to the back of the engine. I have it made up, I just have to solder it together, and from what I can tell right now, it looks much cleaner. I can get away with it though, because all of my sensors are on the very front of the engine by the TB, or under the intake, or at the very back of the enigne. I should have taken pics with the test fit, but I will get pics when I am done.

[The Dark Side of Will]

I usually run my harness through the stock bulkhead pass through at the top center of the firewall and then route around the engine as required.

I prefer to attach the harness to the engine, but I do agree that it should be routed based on aesthetic considerations.

[Aaron]

I usually run my harness through the stock bulkhead pass through at the top center of the firewall and then route around the engine as required.

This is how I did mine too. I don't particularly like it, since that is a tight area with a lot of heat, but it's easy.

Series did his a lot different, he actually relocated the C500, and ran the wires in completely different routes. You'd need to talk to him to get specifics though.

[The Dark Side of Will]

Nothing wrong with changing the wiring routing for a custom project. GM's routing sucks in general and uses way more copper than necessary.
I design my harnesses for the lowest common denominator, which is the stock connector locations.

[Series8217]

I unbolted everything from the battery area and moved it all down to the area behind the right side quarter panel. You don't have to change any of the chassis wiring. It reaches with the factory wiring. You just need to make a few holes and screw the power distribution block and C500 connector to the chassis. It's very easy. Very few wires need to be extended on the engine harness and it cleans stuff up a lot. My ECM is mounted down there too.
My engine harness goes along the front firewall and reaches out to the motor to connect to the oil pressure sender, coolant temp sender, and starter solenoid. A bundle of wires goes up to the area where the engine and transmission meet, hidden under the crossover pipe, to the VSS, backup light switch, and O2 sensor.
The alternator, knock sensor, and CPS wires go along the right cradle rail to behind the harmonic balancer, and up the back side of the motor.
The fuel injection miniharness goes over the front cam carrier and down along the firewall to connectors at the corner of the firewall and the right side framerail.
Power and ground for the starter comes from the front of the car and bolts to the starter and a bellhousing stud on the front side of the transmission. A power cable runs from the starter to the power distribution block to provide power for the rest of the car. The alternator power wire is integrated into the rest of the chassis/engine harness and goes to the power distribution block.
Pretty much the only visible wiring is the bundle from the fuel injection harness.
It takes about 10 minutes to disconnect everything, and 15 minutes to run the whole harness once the engine is reinstalled. Nothing needs to be removed from the chassis wiring or ECM to install or remove the engine.. just unplug the few sebsirs on the engine, remove the power cables from the starter and alternator, unplug the two miniharness connectors, and its all free.


See pics here:
http://www.pbase.com/series8217/engineswap2

[fieroguru]

On my blue car, I relocated the 500 connector, fuel/AC relays, power distribution, etc to the center console (ECM is still there too) and ran the rear tail light harness through the double firewall section.

That allowed for a single bulkhead connector and it was relocated down by the shifter cables.

The harness has 3 legs:
1. Runs under the exhaust and along the block to the Alt, AC, O2, Starter, Knock, oil pressure
2. Picks up the coil/dist and runs along the front side of the intake manifold picking up the rest of the efi stuff.
3. Runs over the bellhousing area of the block and picks up the VSS and temp sender, O2 and reverse switch

[Unsafe At Any Speed]

Nice job guys. I love clean engine compartments and wire tuck jobs. For possible inspiration, this is one of the best examples I've ever seen (not Fiero, but still):

[Unsafe At Any Speed]

double post.

[The Dark Side of Will]

In my opinion, wiring doesn't necessarily have to be hidden... It just needs to look like someone paid attention to it.

[Pyrthian]

the reason you want to keep the wiring tight against the motor is to keep it out of the way when wrenching. and, once you get rid of the "junk" - there really arent many wires left.

[Jinxmutt]

VW guys do this all the time. They come up with some pretty crazy ideas to hide everything in the engine bay other than the engine.

for example...




I prefer to have things accessible just very neat, not run everywhere all loose with cut wires sticking out.

[Jinxmutt]

So I just took apart this mustang wiring harness and its wrapped with non-adhesive tape.

I wish GM used this stuff. I pulled it all off and the wires aren't nasty and a pita to work with like the fiero stuff is when you pull the tape off. I want to use this stuff when i build my new harness. I checked a few places but its all about $15 per roll. Its definitely worth the price if any repairs are needed, thats for sure. Its just weird that I can get 3m adhesive 10 pack at Home Depot for $5 but I can't get it without the adhesive.

Does anyone know the technical name for this tape / wrap stuff so I can try to find it cheaper online? I did a quick search but the results were for OEM replacement tape used on old cars as sort of a 'restoration part' aka expensive.

[Series8217]

Do you really need any wrap on there? I just stuff my wires in convoluted tubing and call it done.
You can put spiral wrap underneath if you want to keep the tubing from possibly chafing the wires.

[p8ntman442]

$1.35 per roll for non adhesive tape at allelectronics.com

Direct link here
http://www.allelectronics.com/cgi-bin/i ... #39;_.html

or cold shrink stretch tape for $9.95/roll
http://www.allelectronics.com/cgi-bin/i ... TAPE_.html

[Jinxmutt]

I like the cleanliness of the wrap. I use the tubing too but the creases fill with dirt and they're tough to clean. Once the tubing is wrapped with tape they can be simply wiped down. Plus I like the smoother look.

That first link is adhesive, and the 2nd one is damn pricey. I don't need moisture seal, just some damn 1" roll vinyl, grr.

[Nashco]

http://www.allelectronics.com/cgi-bin/i ... TAPE_.html

http://www.tapebrothers.com/Dry-Vinyl-Tapes-s/282.htm

[Jinxmutt]

http://www.allelectronics.com/cgi-bin/i ... TAPE_.html

Perfect!!

[Unsafe At Any Speed]

Just wanted to add these to the thread.

[Blue Shift]

VW guys do this all the time. They come up with some pretty crazy ideas to hide everything in the engine bay other than the engine.

for example...




I prefer to have things accessible just very neat, not run everywhere all loose with cut wires sticking out.

Man, some people must get a perverse satisfaction in trying to piss themselves off! :la:

[The Dark Side of Will]

http://www.allelectronics.com/cgi-bin/i ... TAPE_.html

http://www.tapebrothers.com/Dry-Vinyl-Tapes-s/282.htm

Added to the hard to find parts/materials list.