Finding pigtails

I have need to interface with a module which has a molex picoblade 9 bin connector (the correct interfacing part is #51021-0900) I bought a few 51021-0900 from Digikey and bought the correct pin sockets as well. But it requires extreme skill and patience or a $200 tool to crimp those ends onto wire. I've tried it, I lack the needed skill w/o the crimper. I'd like to find some pigtails with this end on them. I've scoured the internet to no avail. Does anyone know of where I might find such things? Do I really need to break down and buy the crimping tool and some wire? (Well, if I have to go this route I plan to use ethernet cabling as it's about the correct wire gauge and 8 wires. I only really need 6 out of 9 pins anyway...) I've tried looking in the Digikey catalog but haven't seen what I need...

Replying to myself...

I still have not found a source for pigtails with the correct connector on them but I did find a fairly cheap crimp tool in the digikey catalog which appears to be able to crimp the ends that I've got.

It's like $60 instead of the way over priced $220 that Molex wants for their crimper.

It appears to me that this $60 crimper will will fine for me. Does anyone think any differently?

Thanks for any information and help anyone can provide!

I haven’t crimped the connectors you are dealign with, but I have done a few of the typical 0.1" square post header type connectors.

I’ve found this tool to be adequate to the task of crimping the 0.1" pins and DB-style pins. It’s not as nice as the Amp tool, but it’s $8.75 instead of $200, too.

I check surplus places like,, and, just to name a few I’ve done business with, for cables that meet my needs at cheap prices. Don’t forget about scavenging old electronics for parts.

Another option may be to simply desolder the connector that’s on the board and replace it with one that’s easier to work with. If it’s a small pitch device (like your appears to be) it may be tough, but if the pins are on 0.1" centers you have lots of options. You may be able to solder wires directly to the board to replace the offending header.


I'm giving that tool a try (just ordered it). It looks pretty similar to the tool I found at Digikey but much cheaper. It can't hurt to give it a try. Thanks!

I got the tool but I'm having a really hard time using it. I might have gotten some sort of instructions with it but I left them at work... I suppose I'll have to look carefully.

It seems like it doesn't quite crimp tight enough to crimp my molex pico connectors onto 26 ga wire. If worst comes to worst I might try to use something like .006 shim steel to make the tool crimp a little harder.

I also opted for a cheap crimp tool (different version) and had some hit & miss results with it.

After some maddening issues with bad cables (and worse, intermittently bad cables) I have a little routine that seems to work.

  1. strip the wires as usual (1/16 of an inch or so) and do the crimp - first on the wire insulation and then shift the connector to do the bare wire crimp

  2. with needle-nosed pliers I then “power crimp” (e.g. flatten :wink: ) the crimp at the bare wire point to make sure the contact is solid.

  3. examine under a magnifying glass to see that the wire is captured/held by the crimp

  4. test it with a continuity tester (multimeter) (!!!)

I tried actually soldering after crimping but that is messy and overkill. Haven’t had any issues since I started this and it gets faster with practice.

I tried actually soldering after crimping but that is messy and overkill.

I've had cases where crimp + solder seemed to cause a failure - it sometimes seems to result in a brittle joint that breaks easily.

I've since dropped back to a method vaguely similar to yours, although not so well thought out or documented. Mine is pretty much "squeeze it until it looks right." :)


agree about the soldering - (brittle, etc) - and can also make it hard to fit it into the connector housing.

Oh - one other thing I have learned from bitter (gnashing of teeth... ;-) ) experience: use polarized, locking connectors. The .1 Molex connectors are fine but they can slip. I've begun using Philmore locking connectors (Molex probably makes the same) and it just reduces one more variable of things that go wrong.


Yep, locking connectors are one of the things I tend to preach about to our students building balloon payloads.

Hot glue will convert a non-locking connector to a locked connector, though it can be a bit difficult to remove.

A standard molex can be made polarized by leaving out a pin on the header, and stopping up the corresponding hole on the connector shell. There's a special plug made for that purpose, but I've used the end of a toothpick superglued in place with satisfactory results.