Hey guys,
I'm new here...I signed up because I feel like I've exhausted all efforts on this problem.
2002 ex coupe, the interior fan won't work.

I checked the blower motor, it's good.
I replaced the fan relay under the hood, that's not the problem.
I even bought a new climate control unit off ebay, thinking the switch was bad....that didn't correct it.

Heres my problem. The interior fan won't work regardless of what setting it's on. You can turn it from low to high, not once does the blower motor spin. So now, I'm thinking, maybe it's the blower resistor? But if it's the resistor, it should at least work on high (right?)

Man I dont know what to do...please help!!

 

check to see if things are grounded and you may have a bad wire. you're gonna have to trace it by hand to see if you have a bad wire

 

hmm, a bad wire..
a bad wire under the dash possibly? I never thought of that, but how would that even occur? I don't even know where to start there, all those harnesses and wrapped up bundles. Talk about a true halloween fright! haha

What about the resistor? any thoughts on that being bad?

Thanks

 

Check the wiring to the blower motor. Generally when the power transistor/resistor pack goes out, you will not have speed 1,2,3 but you will have full speed b/c full speed does not go through a resistor. You need to get a wiring diagram and trace the wiring back until you get power. The part where you go from power to no power is the part that is malfunctioning. Just guessing which part might be bad will make for a very long and expensive fix. You need to user a more systematic approach to diagnostics. Instead of replacing the relay, you can check if it works by checking the resistance of the coil in the relay. Then check if the relay click closed when voltage is applied to the coil.

 

In 1996-2000 Civics, there is a fuse in both the under-hood and under-dash fuse/relay boxes that control this circuit. Have you checked both, if the 2002 Civic is the same.

Finally, a bad wire connecting the fan switch to the blower motor is also a possibility, as mentioned by AgentofDarkness.

 

my relay just went bad on my 99, replaced it and i was all good. Check the relay in the engine bay fuse box

 

this is what you do,, first off chk the fuses underhood fuse box # 12 40 amps ,, also underdash fuse box # 14 10 amps .. if fuses are ok..

the blower motor gets its power from the blower motor relay on the blue /white wire . and it gets its ground through the blower transistor blue/black wire so get a test lite turn ign switch on blower fan speed on and chk to see if you get BOTH power and ground on those wires ,, if you do you got a bad motor

if you do not get ground jump the black wire at transistor to the blue/black wire that goes to motor if motor works you got a bad transistor

if you do not get power , give power source at the blue/white wire if motor comes on you could have a bad relay or bad wiring from relay to motor .. also if you get no power at the middle of under dash there is a brown connector with a single wire blue/white comes in and goes out, make sure that connector is plugged in properly

try this and let us know

 

Thanks for all the helpful advice, I'm heading to work now...so when I get home I'll see if I can try out your suggestions.