I was just looking for more ideas on how to hide the wiring and ecu on my 67 chevelle. I was just thinking of putting a hole through the firewall to run the ecu connectors but it would take a pretty large hole to do that. Any other ideas on how to clean up some of the wiring and hiding the ecu? I left the wiring all the stock length when I build the car a few years ago. It is a truck engine with a 4l80e and dbw throttle.

 

I have a similar issue with my jaguar swap. There is a large hole 6x8 inches in the firewall that used to have ecu and relay box bolted onto it. I am going to move the relays back into the car interior and bolt a flat aluminum plate over the hole. For a grommet, I am looking at the ones used on cars to run wires between the door and chassis and on the rear door of a suburban. They are clean, simple and cheap.

Here is another affordable option.

http://www.sealsit.com/grommet_split.asp

 

you can squeeze the pcm connectors one at a time through about a 1.5" hole.

Take a hole saw and drill few different sized holes through some wood and test it out to see.

Then use the grommets aknovaman posted in the link.

 

I used the hole for clutch master cylinder under brake booster on my 67 camaro has 2 screws holding it on and harness went through no issues.

 

Depin the connectors and route them one wire at a time so you only need a hole big enough of the wire bundle. Don't try passing the connector end through a hole.

Another option is an Amphenol type connector. Used on military grade stuff. Completely waterproof and completely seals the interior from the exterior. Would allow pulling an engine with the wiring in tact.

http://www.mouser.com/Amphenol/

 

I used an AMP connector similar to the ones Popnwood suggested. It made removal of the engine very easy. All I had to do was disconnect two connectors and the motor was free.

 

Do you have any part #s? Also I assume you splice the wires and make sure each side is the same, correct?

 

One of these threads may help:

https://ls1tech.com/forums/conversio...pass-thru.html

https://ls1tech.com/forums/conversio...l-grommet.html

 

I would hide the ECu inside the fender if possible, on top of the inner fender of course, and run the interior wiring thru the speedo cable hole.

 

Amp connectors are expensive relative to other options. Plus they need a special crump tool to on 80 male or so wires and another 80 on the female side. More work than its worth cause I am lazy and cheap.

 

Plus it's 3 more potential spots in each wire (2 crimps and a pin set) for corrosion which leads to increased resistance which leads to skewed ohm readings and lost voltage. I did the Seals-it grommet and will always use that from now on...

 

Amp connectors are watertight. The military uses them everywhere. I calibrate jet engine dyno's that are outside in jungle environment and they do just fine for years. Then bad part is the human factor of a guy assembling the connectors for the first time and screwing up the seals to ruining the pins.

But I am cheap so I will go with OEM or seals it.

 

thanks for all the ideas guys. I will have to look under the dash again and see how long my wiring is.

 

I like to run my harnesses through the trans tunnel just behind the fire wall. Saves length on the harness, clean engine bay, the large hole can be plated/sealed up and concealed by carpet then you can run the comp under the seat or dash.

 

I used a seals-it grommet from summit. Worked great and the harness connectors will fit through the hole one at a time.

 

Great info thank you

Here is the link to Summit for the Seals-It Grommets

 

Awesome info, I have been scratching my head for awhile on the best way to run all the pcm wires into the car, thought about a bulkhead connector similar to the amp connectors, but the added contact points and complexity worries me, thx for the info and links

 

seals it split worked well for me too. almost hidden with BIG OL' truck intake on it.

 

Check McMaster-Carr in their pipe grommets, lots of them in different sizes, the one I need is .96 cents. also used by some of the harness builders...

 

On my 67 skylark I was able to open up the hole where the heater blower wire came through to an 1 1/4". start with the harness in the car and feed it out into the engine bay. There is not much room to mount the ECU and TCM and the fuse box without giving up your entire glovebox. I wish I had left the ECM and TCM in the engine bay and may have no choice but to move into the engine bay in order to fit AC system.