Make this adjustment before you start driving and while the day/night lever is in the day position.
Pull the day/night lever towards you to reduce glare from the headlights of the vehicles behind you during night driving.
Remember that you lose some rearview clarity in the night position.
Hyundai Elantra AD (2016-2020) Service Manual: Height Adjust Components and Components Location
Component Location
1. Height adjust
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Hyundai Elantra AD (2016-2020) Service Manual: Evaporator Core Repair procedures
Replacement
1.
Disconnect the negative (-) battery terminal.
2.
Remove the heater and blower assembly.
(Refer to Heater - "Heater Unit")
3.
Remove the heater unit lower case (A) after loosening the mounting screws.
4.
Pull out the evaporator core (A) from the heater unit.
5.
T ...