QwkTrip

iTrader: (22)

I was swapping out pedals when I noticed a body plug at about 7 O'clock position from clutch hole when looking from inside of car. Seems like a really nice spot to bring wiring through. Any reason I've never seen anybody do that? Extending harness is the same work, whether it is 2 inches or 10 feet.

BlueMagicSS

Most likely because it's so far from where the PCM is mounted under the dash on the passenger side. The more wiring you have, the more issues you have, more resistance, harder to diagnose a problem, along with a higher cost for the added wires, etc, etc. It's way easier to just drill a hole and call it a day.

-Matt

QwkTrip

iTrader: (22)

I won't put a hole under the AC box. It is a terrible place. It's hot next to headers, right on the rail where water will collect, and looks like crap from inside because you can see it.

I've considered mounting the PCM inside the passenger side fender. But the pass-through on the driver side is interesting. As far as wire length, I don't think it takes hardly more wire, if any, compared to running down through the kick panel. Selecting correct wire size is key to voltage drops. And there will be no need to troubleshoot a solid run of wire behind the dash. Keep the solders where it can be accessed.

jamieschott

iTrader: (2)

Interesting thought... Had I not already have mine done, I would consider that.

STREETDEMON

you can't see where my harness comes through under the AC box, if done correctly you can hide the wires just fine in the cab. bore the hole high enough off the rail, and you won't have water issues either.

but its all personal preference, and its YOUR project!

Brando5641

iTrader: (-1)

I will be drilling the hole under the ac box. Im not really looking forward to doing it but it will look better in the end....

ghettocruiser

iTrader: (4)

Ive been using the location under the HVAC box since car #1. And my custom HVAC set up leaves less room than the original box.

NEVER had any issues with the headers, tho I did wrap the harness in that area. And in my opinion it looks pretty good inside. A little cleaning up of the wiring, and some careful trimming, and it can look clean.



Ive since re-wrapped this even better because I didnt like how it looked.



Here's what everyone else sees...



But like stated...its your car! If you want to relocate things, its not a huge deal. Just gotta lengthen some wires/re-wrap the harness and you'll be all set!

If you do something new make sure you document for the future guys!

J.

five7kid

iTrader: (14)

If you're talking about relocating the PCM, it makes more sense to me to use the original ECM pass-through in the passenger kick panel than it does to go all the way over to the driver side.

If you're leaving the PCM in the engine compartment and talking about the instrument panel functions, then perhaps your existing hole idea makes a little more sense.

This is where I routed mine on the LS1/T56 car, in which I relocated the PCM to the passenger compartment. Although I haven't driven it in the rain a lot, I've never had a problem with water getting inside the car. It isn't that close to the headers (which are ceramic coated), but the silver tape is heat reflecting just to be sure.



I was in a bit of a rush to finish up the LS1/4L60E swap, so I left the PCM in the engine compartment. Perhaps one day I'll get it moved into the passenger compartment.

QwkTrip

iTrader: (22)

Passenger side kick panel is sealed up tight because water spray comes off the tire. I'm worried if I remove the original connector that I'll never get that sealed up again. I would prefer to use that spot, though. How have you guys seen it sealed up after running harness through?

ghettocruiser

iTrader: (4)

Im passing some of the harness through there. The same two connectors that go through that same spot on a 4th gen actually.

To seal mine up, I made square piece of aluminum, with a round hole in the middle. I "sealed" that piece to the area with the big square hole with some RTV. Then I was free to use any conventional round grommet to seal up the wires that I passed through. A bead of RTV is more than enough to hold the panel firmly, yet can be removed if you need to adjust the hole or something.

You might be able to find some type of square/rectangle grommet from a specialty place like "seals it" or whatever that place is called that makes the nice pass throughs and grommets. Not sure though.

J.

five7kid

iTrader: (14)

You could take a junk 3rd gen harness ECM with that connector, cut the wires off long on each side, and splice in the 4th gen wires using the 3rd gen wires that pass through the bulkhead connector.

QwkTrip

iTrader: (22)

Not enough pins in the connector, unfortunately.

five7kid

iTrader: (14)

Or, dig out the 3rd gen wires, run your PCM wires through it, re-pot it.

QwkTrip

iTrader: (22)

Interesting...

Never thought about just potting the wires in permanently.

ghettocruiser

iTrader: (4)

Found a pic that sorta shows how I did it. Obviously Im not passing as many wires through as the main harness...but it could be changed to fit whatever will pass through the stock opening.



You can see the little silver square. Thats sealed to the body, leaving a nice round hole to mount a grommet in.

Just wanted to illustrate.

I like the idea of gutting the thirdgen bulkhead for that area and making it work though. Might be kind of difficult to remove the harness if you really seal the wires into it. But It would be a nice clean install for sure.

J.

513camarors91

iTrader: (1)

i think im going to run it the way the original 3rd gen harness ran...i looks clean to me and it looks more factory...

five7kid

iTrader: (14)

I put disconnect terminals on the wires so it could be removed.

ghettocruiser

iTrader: (4)

Disconnects on the main PCM part of the harness?? Thats what we're talking about passing through there right? Or did I misunderstand what QwkTrip was gettin at?

I might be deleting my A/C...in which case my hole and wiring might look a little funky from the engine bay. Might have to figure something new out at that point.

J.

five7kid

iTrader: (14)

Ah, should have explained. I used it for the non-PCM pass-throughs to the instruments. That car has the PCM in the engine compartment.

For a PCM harness, you should be able to pass the PCM connectors through the hole. It's a lot bigger than the hole I punched through the firewall for the other car. In order to use it, you'd have to lengthen the PCM wires, so that's a perfect time to run them through the bulkhead connector.

five7kid

iTrader: (14)

Not like this is an original idea:

https://www.thirdgen.org/forums/ltx-...p-3rd-gen.html

Post #2.

HP52TA

iTrader: (4)

Reuse your stock connector in the stock location.

Remove the connector from the body and heat it with a heat gun until it is hot to touch. The glue inside will start to ooze out of the small center hole when hot enough. This softens the glue inside the connector allowing you to pry it apart. There are clips on each side of the connector which must be unlatched prior to prying.

Once you have it apart, pull the wires free from the center comb and clean up the comb for reuse.

String you new PCM wires in the center comb for reinstallation. I used "duct seal" to reseal the connector. Duct seal can be purchased from any electrical supplier; it is used for sealing conduit in electrical installations and remains pliable.


Here is a pic of the connector apart with the wiring and duct seal already in place, ready for the second half of the connector to be installed.

DeanJ

This is what I did. I sealed it back up with 3M urethane for windows. I routed the harness just like the original.

QwkTrip

iTrader: (22)

Appreciate the input, folks. Gives me some ideas. Thanks!

bungy74

i hope this question doesn't sound too dumb, but what do you mean by re-pot ?

bungy74

i hope this question doesn't sound too dumb, but what do you mean by re-pot ?

QwkTrip

iTrader: (22)

"Potting" is a water proof filler material inside the connector. Usually a sticky gelatin material. It stops moisture ingress and corrosion.