'99 I30 Darlington location

[wheiss]

Hi, I've searched the archives and not found an answer - my '99 I30 heater/AC fan quit - the environmental controls think they are controlling the fan but don't. Voltage at the fan is only about .25 volts and goes up slightly with a command for lower fan speed (backwards). I tried swapping out the enviro control panel and no change. I am thinking a control amplifier or Darlington Resistor. Anyone know if the '99 I30 uses such and where it is located? Thanks.

[goody90q45]

What you're looking for is a fan control amplifier. The darlington resistor is a small component of the amp. I can't speak for the I30 but on the Q45 it's mounted in the airbox behind the glovebox and senses air flow being pushed through by the blower motor.

On the Q it's about a 1.5" x 3" unit held in by a plug and 2 screws/bolts. You'll see it as soon as you pull the glovebox out. If you have a FSM it can be found in the "location of electrical components" drawing in the rear of the EL section.

[Q45tech]

Darlington is not a resistor but a name for a method of connecting 2 transistors [pairs] in " a Darlington Configuration"

The Darlington configuration was invented by Bell Laboratories engineer Sidney Darlington in 1953.

The beta or Hfe is multiplied so a tiny current can control a large current such as a 20 ampere fan.