WTF is up with these wires?

Gentleman Rogue · Post by **Gentleman Rogue** » Sun Dec 13, 2009 9:32 pm

im in the middle of stripping down and rerouting the wiring harness in my truck, and i have ran into a couple of those big thick brown wires with the white stripe that house a smaller wire(or sometimes two), and have the other wire strands running through it that are grounded on the ends. what is the purpose of these? do they really have to be grounded? i'd like to strip the harness down to the absolute bare essentials(eventually want to even do away with the stock gauge cluster).

also, most of the wires in my harness seem to be all tangled and entwined with eachother, which is driving me nuts. i was able to untangle a few of the branches, but some of the others are really mixed up. im half tempted to cut all the wires at the plugs, straighten them all out, and reconnect them at the right length afterwards, but it sounds like a shit ton of extra work. did anyone find any creative ways around this? or did you guys just re-bundle them and call it a day?

lastly, where did you guys end up mounting your ECU? i would have liked to mount mine in the center of the dash like in the car, but it doesnt look like i'll have enough wire to put it that far into the cab.

imput would be greatly appreciated!

boise-nic · Post by **boise-nic** » Mon Dec 14, 2009 7:31 pm

I used the stock ECU case and just put the DSM ecu guts in it. This way lets you use the stock mounting location and no one knows that its not the trucks ECU. Kinda stealthy.

Hmm...thick brown wire with more wire in it... Can't help you much there. I actually put the entire wire harness on my engine before I put the motor in the truck. All I can say is keep poking around with a multimeter and see where you have conductivity. Most wires will trace back somehow to the fuse panel down by the hood latch. The electrical part always takes the longest. I've spent the better part of a month just tracing circuts.

89coltgt · Post by **89coltgt** » Mon Dec 14, 2009 10:33 pm

The thick brown cables that have a outer shield are for the o2 sensor and knock sensor, these must be grounded on one end only, if they are not, you will have a bunch of noise induced into those circuits.

I too am very anal about the harness, but I see no reason to cut wires that are not necessary, once you eliminate all of the unnecessary wiring, it will not really look that bad. Are you running the isc?

boise-nic · Post by **boise-nic** » Tue Dec 15, 2009 7:13 pm

89coltgt wrote:The thick brown cables that have a outer shield are for the o2 sensor and knock sensor, these must be grounded on one end only, if they are not, you will have a bunch of noise induced into those circuits.

I too am very anal about the harness, but I see no reason to cut wires that are not necessary, once you eliminate all of the unnecessary wiring, it will not really look that bad. Are you running the isc?

Grounding should be a non-issue since both the 02 and knock sensor just plug into the wiring harness plugs right? If you are having to cut them, I think you may be doing something incorrect. They should be grounded through the ECU or just by the casing.

89coltgt · Post by **89coltgt** » Tue Dec 15, 2009 8:04 pm

boise-nic wrote:
89coltgt wrote:The thick brown cables that have a outer shield are for the o2 sensor and knock sensor, these must be grounded on one end only, if they are not, you will have a bunch of noise induced into those circuits.

I too am very anal about the harness, but I see no reason to cut wires that are not necessary, once you eliminate all of the unnecessary wiring, it will not really look that bad. Are you running the isc?
Grounding should be a non-issue since both the 02 and knock sensor just plug into the wiring harness plugs right? If you are having to cut them, I think you may be doing something incorrect. They should be grounded through the ECU or just by the casing.

These are grounded on the ecu side of the harness.

Gentleman Rogue · Post by **Gentleman Rogue** » Tue Dec 15, 2009 8:37 pm

Jeremy from hotrodcoffeeshop suggested cutting wires to untangle the whole harness, which sounds like a winner of an idea. i also just remembered today i have a whole second harness that a friend cobbled badly to work in his truck. i think im going to cannibalize his wiring to extend all of mine and still keep the same colored wires! looks like i'll be able to mount the ECU in the bottom center of the dash after all!

boise-nic · Post by **boise-nic** » Fri Dec 18, 2009 2:14 am

Gentleman Rogue wrote:Jeremy from hotrodcoffeeshop suggested cutting wires to untangle the whole harness, which sounds like a winner of an idea. i also just remembered today i have a whole second harness that a friend cobbled badly to work in his truck. i think im going to cannibalize his wiring to extend all of mine and still keep the same colored wires! looks like i'll be able to mount the ECU in the bottom center of the dash after all!

Mine looks pretty cluttered right now because nothing is cut or taken out yet. My thought is transplant the entire harness, get it running, and then eliminate each wire one by one. I'm not a confident not to resolder a wire incorrectly.

Gentleman Rogue · Post by **Gentleman Rogue** » Sun Dec 20, 2009 9:58 pm

my reasonin was two-fold, in that besides extending the harness to reach further, and untangling it, since i pretty much sparated every plug into its own pigtail connector, it'll be easy to route each wire/plug to wherever it needs to go, and will easily be able to see how long to make some wires. i have some pics i took in the middle of this:

Gentleman Rogue · Post by **Gentleman Rogue** » Sun Dec 20, 2009 9:59 pm

my reasonin was two-fold, in that besides extending the harness to reach further, and untangling it, since i pretty much sparated every plug into its own pigtail connector, it'll be easy to route each wire/plug to wherever it needs to go, and will easily be able to see how long to make some wires. i have some pics i took in the middle of this:

boise-nic · Post by **boise-nic** » Mon Dec 21, 2009 7:46 pm

Hmm...pics not working or is it just me?

Gentleman Rogue · Post by **Gentleman Rogue** » Mon Dec 21, 2009 11:52 pm

theyre working on both posts for me, can anyone else see them?q