'73 Oldsmobile Custom Cruiser powered tail gate amperage

Hey all,
Due to various electrical issues (and previous owners mess) I'm undertaking the enormous task of re-wiring my car, although bit by bit and starting with the tailgate.

There's an issue within the system somewhere although the motors seem to work ok when I put a powered probe to the terminals.
Just for future reference, are these special motors or are they just a standard window motor with a specific end on them? I haven't tried yet but I assume I can disassemble them and refit the gear to something else.

Main question
Does anyone know what amperage these motors are meant to be pulling in? I don't want to use a feeble cable or fuse for it, but equally don't want to go massively overkill for the sake of it.

Thanks for any help

 

The motors are standard GM design motors, so rebuilding is possible if you can find parts. The gear drive, if it's plastic (later motors could be installed), may be worn or even broken.
Typically, a window motor draws around 7-9 amps continuous, with an initial peak double the continuous rating, which is why the circuit is generally protected by a circuit breaker instead of a fuse. I think it's 25 amps?

 

This may be of some help. This is the wiring circuitry for the 1973 Custom Cruiser rear window and power tailgate from the 1973 Fisher Body Service Manual. According to the manual, the window and tailgate motors have internal circuit breakers, and the wiring itself is also protected by a circuit breaker.

The manual does not say anywhere that I can find, but I'm guessing the number codes on the various wires indicate the wire gauge. For example, at the very top of this diagram, the wire is labeled "183-12 LGT.BLU." I don't know what the 183 is, but I'm guessing the 12 means 12-gauge and, of course, LGT BLU means light blue. The colors of all the wires are indicated, and pretty much all of them are 12 gauge. One exception is a wire shown down at the bottom labeled "60-10 ORN/BLK," which I assume means a 10-gauge wire, orange/black striped.

In looking at the diagram, I'm thinking that the first number, the three-digit number, just labels the wire in the diagram so you can more easily follow it through the circuit. Note that, for example, 183-12 LGT/BLU is both at the top of the diagram and then again among the three wires at the bottom of the diagram. It also appears elsewhere.