ADC circuit help " is this possible "

[pyrogeek]

ok, sorry, i know it measures voltage and resistance effects voltage. so, i guess i will try to explain what im trying to convey. lol

basically i need to test a circuit, to see if its open or closed. the item that closes the circuit is an ematch and they are only 3 ohms, and there could be multiple ematches in series or parallel, i was thinking it would be nice to be able to tell by the adc reading, how many and maybe how they are wired. i was also thinking of using just a simple ressistive voltage divider, where R2 would be the ematch and R1 would be 10k. Vdd 3.3 , Vref 3.3 maybe less. Vout would go to the adc pin. there would also be a diode in series with R1 and R2, the adc pin would connect after R1, have to shield the pic (18lf6622 ) from the 24Vdc that would also be there every now and then. When i do the math, it is a drastic change when going from R2 being 0 and R2 being 3 ohms, but a very small change when R2 changes from 3 to 6 ohms or even 9 ohms. So what im wondering is will the adc even register this small of a change?