Wiring harness firewall passthrough
 

Hello friends, I am adding an additional 5-wire harness wrapped in fire sleeve for my extra oil pressure and oil temperature sensors. This assembly is roughly 3/4" thick.

I would like to pass this into the cabin for wiring into ECU/Gauges, but I need a suitable location to pass the wires through. The car does have A/C so using those grommets is not possible. Likely would need to drill a new hole into the firewall and use a rubber hose as a grommet. Has anyone done this, and do you have any suitable locations for me to drill through OR pass these wires through?

That's pretty thick for five wires .... ?

I have used the main harness rubber grommet mostly, or any other harness grommet convenient to my routing. Stop the sleeve ahead of your chosen grommet, restart after, IF needed, and it should be doable without major drama.

It's the five wires plus the sleeve, I wanted to try and use it to wrap the harness to keep it all together. Probably could have just used heat shrink, tbh.

UPDATE: Removed the sleeve. Honestly it was just getting in the way. I can wrap the harness in specific spots if necessary.

However, the thickest part of the harness is where the insulated crimps are, and that's about 1/2 inch thick. Still a decently sized turd to pass.

Can you pass it through from the other direction? Or pass them through one wire at a time, then tidy up the bundle after they are all through?

Probably best to keep them together

Kinda late for this but with crimps you dont want them all in the same spo . You want to stagger them to prevent the bulge issue.

Check out this short video, what do you think about this idea?

http://imgur.com/gallery/WXDmM2E

EDIT: On second thought, while convenient, this is a bad idea. Great way to let water into the cabin.

You could also try a bulkhead connector, otherwise just buy a grommet and punch a hole. For oil temp and pressure, those wires only need to be ~18-22 gage, make sure you're not using bulky wiring when it's not warranted.

GOOD NEWS:

There is a HUGE empty space just behind the washer tank. In addition, if you remove the glovebox and look straight in, there is a spot that is exposed with no insulation behind it. If you remove the washer tank, you've got plenty of space to drill through it.

You can mark the spot you need to drill with a punch. I didn't have a punch available that was long enough, so I "made" a punch with two 12" extensions, a 1/4" socket, and a phillips driver bit. I then used a hammer to imprint the area to drill the hole.

I then used a stepped drill bit to drill it out to 7/8" and made a grommet by taking a 1" vacuum cap and drilling out the top of it with the stepped drill bit. To get it in, I cinched it down with a hose clamp, put it into the hole, then removed the hose clamp. Worked like a charm!!!!!1

I mean you can also just buy a rubber grommet, they‘re very common in hardware stores in most standard sizes

Yeah but it was 11:30 at night and I wanted to get this shit done