Heater and A/C stopped working

[Tidewater]

Bought 2001 Wrangler Sport TJ. Previous owner admitted the heater blower did not work. Have replaced Heater control switch, resistor and heater blower motor. Turn key on power goes to heater control switch 12+ volts then strangely the power dies away. No power. What on earth could be causing this?

 

[reddvltj]

Bought 2001 Wrangler Sport TJ. Previous owner admitted the heater blower did not work. Have replaced Heater control switch, resistor and heater blower motor. Turn key on power goes to heater control switch 12+ volts then strangely the power dies away. No power. What on earth could be causing this?

Try swapping out the heater blower motor relay under the hood with a known good relay