Expanding on Mike's idea, you could use a LM3914 dot/bar generator which has ten evenly spaced input voltage levels for the ten outputs. You add a series resistor from 12V to the the Jeep switch and from the common to ground. For example 6.04k ohms in series with the 12V input and 7500 ohms series with the ground will give output voltages of (see post below).
You connect the LM3914 Rh to the 12V which will give an input sensitivity of 10 equally spaced trigger points from 1.2V to 12V. The outputs are connected to ground when active so you would need a PNP transistor or P-MOSFET at each of the 5 used outputs (2, 3, 4, 6, 8) to generate the +12V signal. You put the LM3914 in the DOT mode so only one output is active at a time.
Edit: There was an error in the voltage calculations. See below for revised chart.