I'm going to try to consolidate some of the info on parts here and the APEX/Jebao harness tutorial sites (please someone make a comprehensive tutorial on this at some point), I get emails almost daily and people are needing to know how to make them or get a place to buy them. FUTURE pm's won't be responded to on this subject as I'm not on here much lately, but I wanted to put this post up to try to help as much as possible.
Please get started by reading much of this thread.
See a cord that controls two jeabos off one APEX variable speed (ethernet) port at post #145 of this thread.
for anyone making their own Apex cables, you can get 'trim pot' variable resistors rather than using fixed value resistors, to make your voltage dividers with. This give you flexibility with a voltometer to dial in exactly what you want your max output value to be. (cost a couple cents more). If you don't have a voltmeter, don't mess with it, use two resistors of the same value and it will cut the volts in half, (what you want).
It uses the 0-10v channels. So you can use the 0-10v on either the head unit OR the VDM, but you don't have to have the VDM.
Waterproof LED connector:
There are many that look alike, don't buy the wrong ones. The LED connector you want is this: 3x0.75 SQMM LED Light Strips 3 Pin Waterproof Connector Cable I can vouch for the black ones from Aliexpress, they work. I've heard the white ones do NOT.
DC Jack:
For DC jacks you want 5.5mm x 2.1mm female DC jacks. Get the ones that have pigtails already to make your life easier.
Ethernet RJ45 Connector:
You can DIY with a household ethernet crimping set/materials, OR just cut an ethernet cord you have laying around. (Plan ahead for how long you want the distances to be from the APEX, the cord has to be long enough).
Resistors:
4.7K ohm to 10K ohm have all worked great for me. Recently used trim pots and voltmeter to further dial in the max voltage I wanted. (pots also really helpful in providing a reduced voltage to the speed control wire on the pump when running off a back up battery). Alternately you can use an online calculator to pick resistors:
http://www.raltron.com/cust/tools/voltage_divider.asp but this isn't necessary for the harness which just uses a voltage splitter of two of the same value resistors.
There's a new software environment coming out for APEX that should make programming these pumps a lot more fun/flexible. If anyone has Apex Fusion yet, let us know if it helps with programming these pumps!