BMW E36 Final Stage Resistor, Hedgehog replacement DIY guide.
First of all, if your car is right hand drive, then you'll find the Resistor / Hedgehog / Final Stage Unit (FSU) on the passenger side, NOT on the driver's side. (LHD cars are on the drivers side). This guide is for RHD(Right Hand Drive) cars.
1. Remove the panel from underneath your glove box using a Torx screwdriver.
2. Now get your head right in there and looking towards the left hand side rear of the heater box you will see your blower resistor and the wiring/plug that goes to it.
3. If you have the analogue style resistor then they are clipped in, wiggling the plug along with the resistor should see it slide out of the heater box. Digital final stage resistors/Hedgehog type are held in with 3 T20 screws so you'll need to use a T20 Torx stubby screwdriver or ratchet with T20 bit to remove the resistor.
4. Now you can unplug the wiring and begin to refit your new resistor.
If you are unsure which resistor you need then you can tell from which heater control panel you have.
Analogue System resistor is needed if you have this control panel.
Digital final stage resistor is needed if you have this control panel.