How to trouble shoot front blower
There are several reasons for a blower to stop working. Does it work on ANY speed? Does the AC compressor lamp or any of the vent control LEDs still work when using the AC controls? Do ANY of the speed for the blower work or are they all dead?
1st, you wanna check your fuses. There will be fuses in the underhood fusebox marked blower or heater fan, check and repalce as necessary. Also, if the earlier check for working LED bulbs on the AC control panel showed some or all lights dont ever turn on when engine is running, you may have problems with the control system.
if the fuses are good, now you need to test parts. there is a blower motor speed control aka blower resistor that frequently fails on most cars. It is the part that carries the current for all speeds of the blower and regulates speed when commanded. It has to absorb the excess energy to lower speeds and it tends to get very hot and burn out as a result. If it has failed, there will be power IN on one of its wires, and no power OUT on any others. If you have no multimeter or testlight to check things like this, Id recommend taking it to a certified mechanic.
If the control lamps all work that means controls have power, if the blower resistor has no power, fuses or blower relay are the most likely cause. if the blower resistor has power but still no fan, most likely your fan has failed. as a general rule, I replace fans and blower resistors as pairs. fans tend to last longer, but they also get more demanding with age (kinda like people) and that extra demand will burn out the newer resistor much faster than when the fan was newer. it can be alot of time and money to change a blower TWICE, so to be sure it wont fail again, test current, or simply replace the blower fan if it is determined a resistor has failed. (a good fan in theory shouldnt draw enough amperage to burn out a good resistor, EVER, so if the resistor burns, the fan is typically drawing too much power, and even though it works "fine", it will burn the next resistor in a short time as well.).
on Feb 24, 2015