McFly

McFly

Well Known Member
Does anyone have an elegant solution for a firewall penetration for D-sub connectors? In this case it's for a Lightspeed ignition unit. I was thinking of an eyeball but don?t think that is big enough. I want to avoid cutting the harness and re-soldering if possible. Pictures/websites will work too. Thanks.

Hugh
 
Hugh - I am not familiar enough with the Lightspeed system to know if they use D-Subs where the wires are soldered to permanent pin/sockets, or if they are the kind where the pins and sockets are crimped on individually to the wires, and then inserted in the body. If it is the latter, you can get an inexpensive tool to pop them out, feed the wires through without the body, and then reinsert. If the former...disregard...

Paul
 
Ironflight said:
Hugh - I am not familiar enough with the Lightspeed system to know if they use D-Subs where the wires are soldered to permanent pin/sockets, or if they are the kind where the pins and sockets are crimped on individually to the wires, and then inserted in the body. If it is the latter, you can get an inexpensive tool to pop them out, feed the wires through without the body, and then reinsert. If the former...disregard...

Paul
Click to expand...
What you might consider, following Paul's line of thinking is to make your own "jumper" that gets crimped/soldered/inserted/whatever after the primary "cable" is put through.

I have also seen a connector mounted as a "bulkhead" type connector for something else.

Finally, I do know of the Lightspeed boxes being mounted on the forewall and it working. This might not be the RECOMMENDED way for doing it though.

James
 
light speed pass through

i used vans 2 piece gromet sheild after cuting a hole big enough for conecter to fit through.
bob mcmillin RV-9 N535WP 90825 finishing wiring
 
Don't cut Lightspeed cable

McFly,
Don't cut the Lightspeed cable. I did, and Klaus Savier was slightly perturbed that I cut the cable in spite of the written instructions in BIG BLOCK LETTERS(I thought instructions were for wimps...). Klaus had me send the stuff back to be fixed(for free, what a guy!). It is a good idea to talk with the manufacturer before doing anything "original". I ended up doing something similar to chewton.
 
Lighstpeed module location

My advice: Just put the lightspeed module on the firewall. I mounted mine up at the top, right in the center. Avoids the problem nicely.

Jordan Grant
RV-6 N198G
 
Hugh,

I cut the cable. Ran the wire through my firewall wire pass-through, along with a bundle of EGT/CHT/oil/fuel sensor wires and my mag's P-lead wire. I don't know what the big deal is about not cutting it.

I reinstalled a new connector on the cabin side with crimp D-sub pins (instead of solder like the original).

The key here is that you have to make darn well sure you connect it EXACTLY the same as it came from the factory. If memory serves, some of the wires have the same color, since there are two "bundles" within the bundle. This is from memory, so don't hate me if I'm slightly off here... :rolleyes:

But my point is that I cut the stupid thing because the last thing I was gonna do is poke a giant hole in my firewall just to run a wire that could be reconnected on the other side. 900 hours and not a single issue related to this wiring (I did have an issue with my own coil wiring, but that's another story that I think I've already told you about).

Another option that does not require cutting & reconnecting the wire involves running it through one of the little "notches" along the upper outside of the firewall, where the firewall flange is interrupted along the curve. Essentially enlarge one of the notches, slice a snap bushing, and there you go.
 
here's a photo...

EIwires.jpg
 
I cut and re-wired the d-sub. It's not a big deal.

BTW on Clay's picture, I hope you covered this with fire putty eventually. If not, there's zero smoke/fire protection should you experience a fire in your engine compartment.
 
Update

Thanks for some great suggestions. I almost went with Clay's method but I ended up cutting the cord and resoldering. Actually I cut the cord and held the flashlight for a friend who is very skilled with an iron.
 
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