TroyMaynor@aol.com wrote:
>
> Hi All,
> I am planning ahead a bit on the number of wires and connections that will go
> thru the firewall and I need some opinions if you all don't mind. I will have
> a removeable panel and wanted to also be able to disconnect the mag wires
> behind the panel at the firewall. I understand that there would have to be a
> temporary jumper to maintain to keep the mags "dead" while the panel is out.
> The outter shield must be grounded at both ends. If I pass these thru a
> bulkhead connector is it best to ground them on either side of the bulkhead
> connector or pass the outter shield thru its own pin within the connector to
> maintain the outter shield circuit. I'm thinking it doesn't matter. What's
> the opinion of those who've been there?
My 914 manual sez ground the 'mag' wire shields at the engine end
only. I wouldn't bring the mag wires thru the 37-pin item you propose
(below), but rather poke 'em thru the firewall elsewhere for shortest
distance, and thus away from inductive pickup effect adjacent to other
wiring. Use push-on connectors for the mag switch. You can bring the
shields thru a plastic connector, but the shielding is still
interrupted that point, allowing leakage of EMI garbage.
> For the wires coming in to the panel from the systems in the fuselage I have
> a 37 pin "Amp" CPC (or circular plastic connector) Series 1 that I acquirred.
> I won't need all the pin space but it's light weight anyhow. It already has
> about 23 wires and pins installed from it's former use. They are size 20 pins
> and I think they will carry about 10-13 amps. I am looking for an extractor
> tool to remove the old pins and replace them with new ones instead of
> splicing into the existing wire that is there. Any ideas?
An online catalog here (www.digikey.com) has a AMP Series 1 pin
extractor for $17 US. Problem is they show price on even 37-pin CPC
shells at a fraction of that, and you need new pins anyway. If it's
anything like the Molex extractor for their skinny pins, it's a
"percentage shot" as to how many pins you can actually extract! If
you want to salvage the connector you have, as a matter of principle,
you might get lucky at a hobby shop where they may have brass tubing
that fits snugly over the pin and will compress the locking tangs.
For $1, this has saved me from buying another rip-off extractor for
.093" Molex pins. But in your case, it looks like you'd be best off
in just buying new connector shells. The AMP CPC connectors have the
advantage of "thread assist" in pulling them apart. Molex, in like
24-pin variety takes muscle to pull free, and you tend to tug on the
wire crimps (whilst cussing), compromising those connections.
Best,
Fred F.
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