My HVAC only works on setting 4 for heat and a/c. I purchased new controls and just hooked them up but that did not solve the problem. What else could be causing this?

 

Isn't there a resistor or potentiometer that controls the blower fan? That would be my first suspect.

 

Provide all pertinent information about your car and engine:

 

it would help if you told us the year, make, model and trim of your car

but as mentioned above, 99% your blower motor resistor is bad. usually they are behind the glove box

 

It is a 1997 Civic LX. Base Engine

 

OE part# is 79330-SR3-A01. $22 bucks online.
www.hondapartsunlimited.com

 

idk if civics have them but on other cars there is a low speed blower relay and a high speed blower relay

 

resistor for sure...

 

Thanks for the help. For $22 it's worth a shot to try. Sounds like you guys are pretty sure that's the problem though.

 

There are 3 resistors for the lower fan settings. When you turn your switch to 1, 2, or 3, you are drawing the same amount of power. The resistors are there to waste energy that power your fans, thus your fans spin slower. There are only resistors for each 1 to 3 as 4 will give the fan full power.
That is why everyone is saying it is your resistors. Easy check is to pop your old one out and see if there is a break in your coiled wire resistors. If not that, check the low speed relay mentioned above. Another trick is to hit your blower fan with a rubber mallet with the switch on 1, 2, or 3. Don't know if that one works on these cars (it's a trick I used on another).

Good luck.

 

I have a blower resistor bnib. Click my sig or send me a pm.

And yes, its 99.9% likely that's your problem.

 

+.1%

IF the fan ONLY works on high, it's 100% for sure a bad resistor...

Don't forget to update the thread after you replace it, so you can rub dirt in my face if I'm wrong.

 

Why guess?