Watch out 24-36 vdc is on 2 wires. It is dangerous to touch these 2 wires while the motor is moving! Let pro's on moto's do it if you have not done it before.
Maintenance of a motorized dish is this. Using multi-meter (ohm setting) all wires are disconnected and not touching each other; wires have no shorts!
The 2 wires for a sensor are 5vdc and gnd if "reed switch". The 5vdc wire will short to gnd and go to zero, to make a count when connected to a box. These two (2) wires are normally small 14-20 gauge wires; where as the motor wires are normally heavier, from 10-14 gauge; because they need the gauge they are on. This is a requirement of voltage. The count made from a reed switch is a on/off mechanism of the turning magnet wheel, which rotates a magnet and passes this motion to the magnetism in the reed sw to open and close it; on and off, as a count is returned to the stb as gnd or open! The 5vdc goes to zero, or cannot go to zero, then is the "received" counting (how the stb vbox/gbox/4dtv/ works).
A test of "counting" is taking your voltage/amperage/ohm meter; setting it to medium amps (1); interrupting the return wire with your meter; and seeing the count comeback to the stb.
Another, is by taking the end of the cable that plugs into the motor; and using the two wires that hook up to the reed switch; make a continuos "count" or cadence by shorting/opening over and over again these two wires together short and those two wires open; using meter set to ohm's at other end; watch the shorting/open condition.
In Essence : Each stb does all counting the same; but if reed sw; 2 wires provide count to "normally marked" "sense/sen, 5vdc" for a second and "gnd/ground". These two wires must never be connected to any other wire; ever; or the stb box breaks and does not count ever again! this is what is important...and if you plug 12vdc from count circuit of stb u break the reed sw!
And if you have a optical sensor, you need 12vdc/sense/gnd (three wires; 12v power; sense; and ground); it is optical, and motor will not work with the cover off)...and if they are plugged in in-correctly; you can break the stb, box and sensor...On a optical sensor, the 12 vdc provide power to a laser, in the little black box that envelops a small horseshoe area. This is a light; and when the wheel turns; many open/closed conditions happen to the light, run on 12vdc. One wire is the sense or 5vdc end of the light mechanism, and opens/closes when lit or un-lit. Another is the return (part that shorts wire), or ground/gnd; this is tied to a stb's gnd/ground. When the sense/5vdc at the stb/box goes to Ground condition; a count is registered in stb is "how it works"...