Engineering CalculatorsHarness Designer
Connector naming, per-pin wire assignment across multiple branches (including multi-drop splices), and an auto-generated point-to-point wiring schematic with connector naming, pin numbers, and wire specs.
| Pin | Signal | Wire | AWG | Twisted w/ | Drain for | Destination |
|---|---|---|---|---|---|---|
| 1 | — | — | ||||
| 2 | — | — | ||||
| 3 | — | — | ||||
| 4 | — | — | ||||
| 5 | — | — | ||||
| 6 | — | — | ||||
| 7 | — | — | ||||
| 8 | — | — |
New to MIL-DTL-38999? Read the guide: MIL-DTL-38999 Connectors: Contact Sizes, Ratings & Pinouts — a plain-language explainer of the standard behind this calculator.
Contact-size current ratings are sourced from a real MIL-DTL-38999 Series III contact cross-reference catalog. Scope: one dominant contact size per connector with a direct user-entered pin count (no shell/insert-arrangement modelling). Multiple pins may point at the same target pin to form a multi-drop splice — the schematic draws one shared filled junction dot at a single representative anchor pin and a wire from every other spliced pin back to it, which is electrically equivalent to a real splice but not a literal drawing of a splice sleeve/crimp at a separate mid-harness point. A twisted pair routed straight between two connectors is drawn with its two conductors visibly crossing over each other along the run — the standard drafting convention for indicating a twist — rather than a literal helix; an elbow-routed pair keeps parallel lanes with diagonal crossing tick marks, and a pair split across non-adjacent connectors still wires correctly but carries no twist marker. A wire's construction, gauge, and twisted-pair link describe the whole physical wire, so setting them at either end applies to the far end automatically (when a connection is made, a still-default end adopts the configured end's wire spec, and gauges snap to each connector's own contact range). A shielded conductor or twisted shielded pair can be assigned its own drain-wire pin — a real, separately-wired pin like any other, not an abstract flag — drawn as an oval shield marker around the conductor(s) at each end of the run, with a 90° tap from the drain-side oval to the drain pin's own position; the ovals are a symbolic marker, not a to-scale cable jacket drawing. The schematic is a point-to-point wiring diagram (labelled connector boxes with numbered pins), not a to-scale connector face/pin-arrangement drawing — verify final pin arrangement against the manufacturer's insert arrangement drawing.