Engine Harness thru Floor/Firewall
 

Just wondering if some of you could post pictures of grommets or sealing when passing large wire harness thru the floor in particular. Would just like to see how you all are sealing the pass thru
I'm running Ls with GM Performance Wire harness.

Re: Engine Harness thru Floor/Firewall
 

We did the same and made a pass through of sorts. It was a 3x3 square aluminum plate. Cut a 1.25" hole with a hole saw and then cut the plate in half. Lined the inside edges with rubber hose and then filled the opening with Black RTV. I was going to use a real bulk head connector until I read in the instruction that you should not shorten or modify some of the wires, I think due to a specific resistance requirement on certain wire like O2 .

Re: Engine Harness thru Floor/Firewall
 

We ended up cutting the plugs off and just passing the wires through round grommets so that the pass through holes ended up as small as possible. Re-soldered the connectors to the bare wires once they were through. More work, but cleaner result.

http://i.imgur.com/bqiy2ug.jpg

Re: Engine Harness thru Floor/Firewall
 

I'm planning on using these for the larger bundles :
http://static.summitracing.com/globa...20040BK_ml.jpg

Re: Engine Harness thru Floor/Firewall
 

The ecm says, "EZ EFI," ironically, it looks anything but that.

Re: Engine Harness thru Floor/Firewall
 

thanks guys, I was not wanting to disassembly the harness and was thinking of some sort of hatch like dwcsr suggested was also looking at
seals it split grommet.
https://www.google.com/url?sa=i&rct=...59355351428537

Re: Engine Harness thru Floor/Firewall
 

This photo pretty much convinced me I will never have a "modern" electronic engine. Single wire HEI and carb for me....

Re: Engine Harness thru Floor/Firewall
 

here is a picture of mine, The only thing I would do differently is make a drip edge over the opening so water can't run in

Re: Engine Harness thru Floor/Firewall
 

Good ideas here that I stumbled across...http://ls1tech.com/forums/conversion...pass-thru.html

Re: Engine Harness thru Floor/Firewall
 

I drill a 2 1/4 hole I think and used painless plug

Re: Engine Harness thru Floor/Firewall
 

Correction, I used speartechs plug. See bottom of page
http://www.speartech.com/category_s/1825.htm

Re: Engine Harness thru Floor/Firewall
 

I used this one, works great and it has different steps so you can choose what size your final hole is.

Re: Engine Harness thru Floor/Firewall
 

Glad to see this topic since this something I too have been contemplating. I have a harness going to an ECM in the cab and I don't want to take the connectors apart, I would rather pass the entire connector and harness through. I prefer a solution where the harness can be pulled back out easily if need be in the future.

I saw this at a show. I thought it was a cool way to finish off a harness passing through a firewall. It's a boat vent. You can find them on eBay of different sizes.

https://lh3.googleusercontent.com/-d...711_134852.jpg

Re: Engine Harness thru Floor/Firewall
 

That is a great job.
Does your seat lift for easy access?

Re: Engine Harness thru Floor/Firewall
 

I like this, Simple and clean. I see they come in different sizes also

Re: Engine Harness thru Floor/Firewall
 

I've been thinking about using the old fuse block mount and cover that goes on the firewall of 48/50 trucks to cover the hole the harness comes out the firewall through I still have the stock cover I had chromed in 1973 in good shape in my storage cabinet.

That boat vent thing looks good and clean though.

Re: Engine Harness thru Floor/Firewall
 

I ran mine thru the firewall in the fender area using a standard rubber grommet. I filled the space with insulating putty used for construction sealing. It stays in place, but remains pliable if you have to remove it. I also have been using it for metal to metal where the Factory assembly manual shows factory caulking.

Re: Engine Harness thru Floor/Firewall
 

To me half the reason to own and run this old iron is to AVOID things like that as seen above

Re: Engine Harness thru Floor/Firewall
 

I've got this one in my eBay cart, not the cheapest...but it is pretty and I like the functionality.

http://www.ebay.com/itm/272275827081

Re: Engine Harness thru Floor/Firewall
 

This seems very cool. I STILL want as close to NONE of my wires showing in the engine compartment, but I'd use this anyway. $30 isn't gonna break anyone....I think.

Re: Engine Harness thru Floor/Firewall
 

I used a factory s10 harness pass through, it is rubber and pulls tight to the firewall with three bolts. you just cut the same hole in the firewall as the s10 has and bolt it up. It has some goop on the wires to seal it completely, but if you look around in a salvage I bet you can find one similar on most GM and just chop the harness and take the pass through.

http://i266.photobucket.com/albums/i...ps4fcwfqsf.jpg
http://i266.photobucket.com/albums/i...pssfcjhp64.jpg
http://i266.photobucket.com/albums/i...ps03ohlsuf.jpg
http://i266.photobucket.com/albums/i...psjohjntt4.jpg