"Amphenol" is a MIL-spec, metal-bodied, fully waterproof electrical connector available in a variety of configurations. It may be used for RF signals, low voltage signals, light power distribution, and the like. They can be free-hanging/cable-mounted or bulkhead-mounted and gasketed. This is a 19-circuit Amphenol, cable-mounted, and coated OD:
"CPC" is a Circular Plastic Connector - similar to an Amphenol, but made with a plastic body and is
not MIL-spec. However, it is usually slightly cheaper, and almost as durable and is still watertight. This is a 14-circuit female bulkhead-mount CPC:
Caps can be had for bulkhead-mounted connectors - this is why I tend to recomment Amphenols or CPCs for routing power to a roof lightbar or light rack. This allows you to remove the lighting (for whatever reason) and seal off the connector so it doesn't get anything in it. The cap is retained (typically) by a short ball-chain tether, but I'm sure you can use something else. The tether is retained by one of the bulkhead mounting screws.
This is an example of a "dust cap" - it slips over the bulkhead fitting:
The dust cap is
not watertight or weathertight. If you want that, you'll need this plug:
You'll note that the ID of the cap is threaded, and it screws onto the connector for a more positive seal. There is also a rubber gasket in the plug.
While it's possible to keep the weather plug in your glove box or spares box and not have it tethered to the connector, it is preferred that it is tethered - if it should come loose, you won't lose it (unless you've scrubbed the connector off of the bulkhead - in which case, you have larger problems.)
It is possible to get Amphenols/CPCs with mixed-size gage pins - the larger pins would be used for the power supply/distribution leads (up to about 10AWG, typically) and the smaller pins for signal distribution (usually 18-14AWG.)
I don't blame you for "assuming" that a given mod won't pass CA Air Police inspection - I find them onerous and silly myself (having dealt with them for the last twenty years out here...) However, I've also noted that CARB EO numbers are most often required on things that will affect airflow through the engine - exhaust systems, intake mods, camshaft mods, and cylinder heads. Internal parts will pass because they can't be seen, and most CA stroker owners have no trouble getting them to pass biennial emissions inspections - and they don't tell the Techs (they don't need to know anyhow.) You usually do have to tune the engine manangement somewhat - but most of what will want doing is monitoring the FAR while adjusting the MAP supply voltage to trim the fuel delivery - this is a gross adjustment, but it will make it easier for the HEGO to do its job of fine-tuning the fuel delivery. Given the way the HEGO responds to FAR variations, there's really a narrow band where the HEGO signal can trim fuel delivery - you'll have to get it close, and that's where the gross MAP supply voltage adjustment comes in to play. The adjustment may be easily done using a small circuit built around an LM317 adjustable +DC voltage regulator, which can be had at any electronics parts house. I won't go into detail on how to build the circuit - since it's been covered before (as a specific MAP application) online; and there are typically also circuit diagrams on the back of the card. It's a simple circuit, and it can be built in a few minutes with only a bit of skill.
Me being me (and therefore a perfectionist and detail-orientated,) I'd also add a wideband HEGO and a FAR monitor to allow me to monitor the effects of the MAP adjustment, and allow me to make future adjustments as required. Monitoring EGTs can also allow you to do this - but using a WHEGO as a FAR monitor is easier to read (I do want to put a six-cylinder pyrometer-based EGT monitor on as well, but that's more to detect variations between cylinders. I'd also eventually build a MegaSquirt controller - it's a fully-programmable DIY controller, and that would allow me to tune even individual cylinders
a la a programmable late-model GM setup... You can look up MegaSquirt - filter using the developers' names: Bruce Bowling and Al Grippo.)
GLOSSARY
CARB - California Air Resources Board
EGT - Exhaust Gas Temperature
EO - Executive Order. The exemption number applied to "approved" parts by CARB
FAR - Fuel/Air Ratio
HEGO - Heated Exhaust Gas Oxygen sensor
ID - Inside/Inner Diameter
MAP - Manifold Absolute Pressure sensor
OD - Olive Drab (typical military-issue equiment colour)
RF - Radio Frequency
WHEGO - Wideband Heated Exhaust Gas Oxygen sensor
(I do this when I use a lot of abbreviations - I get tired of typing them all out longhand...)
since February of 2013......
