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Molex pins for elevator trim servo

I

iamtheari

Well Known Member
I am having trouble getting the pins that came in the empennage kit for the trim servo inserted into the Molex connector. They go in fine but not far enough to click into place, and those little tiny wires don't make a great platform for pushing the pins with much force.

Probably, I screwed up the crimping by using a cheap tool, and the imperfectly crimped pins are interfering with their own insertion into the connector. I bought a better crimper for future use. But I can't figure out precisely what to order or from where, to get replacement pins. I ordered some from Aircraft Spruce but they are way too big.

Any tips on either inserting the pins into the connector or finding replacement pins? Thanks in advance!
 
I used good tools and still had trouble getting them to lock-in but if carefully done, they will go in far enough to lock in place. Try turning them (changing the orientation) a bit as you are pushing them in. When they have gone far enough, they would lock in place.

Hope this helps.
 
I thought I might run into the same problem. With everything I'd read about the first attempt crimping and inserting pins into Molex connectors, I decided to order a few and practice. With all the variations out there, it was tough to find the right ones. Below is a picture of my packing slip. Pins were and exact match and the plug is the same plug sent by Vans. Freight was more than the cost of the items.

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Make sure they are going in the correct orientation and use a tiny flat head screwdriver to push the pins.
 
Call Steinair. They built the harness for Vans. The tech there was awesome on the phone and explained everything in detail. Went as far as texting me a picture of a properly done crimp. I bought the good parallel jaw pliers from them as well as a bunch of extra pins. Practiced on the pins and exact gauge wire before I did the servo connector. Also bought a bench mounted magnifying glass with a light! Go broke with style.
 
after a few weeks flying, the trim positiion indicator failed and I tracked it down to the plug at the tail cone. One of the wires in the supplied harness just fell out of the plug. I replaced the plug with a d-sub 9-pin connector and all has been well since
 
Use DSUB pins and heatshrink

I used the simple, reliable, cheap and lightweight method by using DSUB pins covered in heatshrink:

(Pics below are on an EGT wire, but this applies to any wires you need to connect).
DSCN2320.JPG


DSCN2322.JPG


It's about as low-profile of a connection as you can get, and still serviceable with basic aviation electrical tools.
 
If there is enough wire to leave a small service loop, then forget the connector and use butt splice connectors, solder core if you have them. This is not an area that will require disassembly and if so, the service loop will accommodate that. Terminal connectors, like the molex plug, are just a place for issues years into service. Keep things simple.
 
Just a thought.

I use the Stein tool for these split terminals and initially had some that did not want to click in. I found the thickness of the tool (length along the terminal) was critical and just a few thousands too close to the pin end, would crush the housing and destroy the retention function. I used a headband magnifier to ensure proper placement and did not have the issue again.
 
In this instance, although I already ordered the pins and connector from Digikey, I'll just eat the $6.00 and eliminate C409P/J by using butt splices from the servo to WH-00073 (the short harness supplied in the kit to get out of the elevator and into the tailcone. I will retain C429P/J so that the elevator can be disconnected from WH-00057 (the aft fuselage wiring harness) when needed.

Incidentally, I found a mistake in the plans while writing this post: Page 10-25, revision 0, figure 2 says to label the connectors on WH-00057 as C410P and C409P. The latter should be C429P. See page 09-24, revision 0, figures 3 and 5. (This is not egregious. It's very obvious what is going on in the plans. My OCD just catches things like that, teh typo in the title of figure 1 on page 10-21, and the fact that page 10-22 does not have steps 4 or 5.) :)
 
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