Originally Posted by RGMN

Deutsch makes the original version of these. When their patent ran out a few years back Amphenol, Molex, and a few other jumped in with copies of these. Some work better than the Deutsch, most don't. Amphenol, when they originally came out, used spiral wound wires on the sockets that worked like a Chinese finger trap. For a high vibration environment this style contact works MUCH better than the bifurcated spring contact used on the Deutsch. I believe Amphenol quit making them due to the higher production costs.

If you use the DTM bodies there are a few things to keep in mind.

• The seals on the connectors are sized for SAE J1128 cable, GPT insulation. If you use something other than SAE J1128 GPT in the connectors you need to check that the seals will work with your wire. Too large of diameter and it will rip the seal, too small and it won't seal properly.
• The DT/DTM/DTP style connectors (I'm using the Deutsch nomenclature as that is what I'm familiar with. The Deutsch are also available from Digi-Key.) require a straight run of wire entering into the connector. If the wire bends too close to the connector it will stress the seal and cause a leak. Typically in situations where you might have the wire bending close to the connector you should use a version with a shrink boot adapter on it as this forces the wire to be straight as it enters the connector. The other thing this helps with is if you get a lot of rapid heating/cooling cycles (think of taking your bike inside after riding on a winter day) the pressure changes inside the connector can force the seals out before the pressure differential vents thru the wires. The shrink boot adapter also prevents this from happening.
• The DTM and DTP style connectors are preferable to the DT. Both have the connector body seal on the pin side while the DT has the seal on the socket side. On the DTM and DTP the seal is static, while the DT the seal has to slide into the mating connector. This makes the DTs much harder to mate and unmate, and risks damage to the seal. If you must use the DT, use the -P012 enhanced seal version. This holds the seal much more firmly and reduces the likelihood of damage.

If you are making single connections Deutsch makes a single connector body called a Jiffy splice. I believe Amphenol makes something similar. These seal single connections very well, and are easy to disassemble if you use machined contacts. But they do require a tool to remove the contacts, and they are larger in diameter than using heat shrink.

If you do decide to use the Deutsch contacts check the pricing on the Ladd Inc/TE website. Their pricing is often substantially less than Digikey or Mouser.