Without the manual, guessing the pinout will short the logic board.
Here’s a forum-style post you could use or adapt: curtis 3501 manual
The Curtis 3501 stores high voltage in its capacitors even after battery disconnect. The manual explicitly states you must wait after disconnecting power before touching the B+ or M- terminals. Ignoring this can be fatal. Without the manual, guessing the pinout will short
: Rectangular case made of black Polycarbonate Resin with a transparent PMMA lens. Connectivity and Interfaces Without the manual
The 3501 typically uses a 24-pin or 10-pin Molex connector. The manual provides a table like this:
For example, a Curtis 3501 labeled "1204M" is vastly different from a "1205M" or an "1212" model, even if the "3501" base number appears. The manual you need depends on: