2001LC
SILVER Star
I also bought the switch (relay was wrong trem to use) from NAPA. Only to find mine started working again on it's own as I keep working the CDL on and off.The relays that we hear clicking behind the glove box control the actuator motor, not the dash light. The light's illuminated when the detector switch on the transfer case is physically depressed by the engaged CDL, so, barring a burnt-out bulb the detector switch is the likely culprit.
Exercising the system is definitely easy "preventative maintenance." I had to replace my CDL detector switch to restore proper operation of my dash light. NAPA p/n NS6421 is the $29 solution, more info here: Center Differential Lock Transfer Indicator Switch Problem