On my 1990 Honda Civic LX I have an issue with the Heater/A/C blower switch I think.
I was in Las Vegas this weekend close to 100 degrees. So A/C is kind of nice. Well I turned on the A/C & blower switch to #4 or HIGH. Well the car A/C cooled down nicely. So I turned down the BLOWER SWITCH to #1 or LOW. Well in short order the A/C quit cooling. I thought I must have a High Head pressure kicking it off. So I washed the condenser all out with a pressure washer @ the car wash. It wasn't real bad. So then I think well I wonder if the FANS are turning on? So I check that all seems OK. Then when I was fooling around checking connections the wife turns the Blower switch to LOW & nothing.
So what I have decided is on the LOW fan speeds the condensing fans work sometimes. So today we drove home with the A/C blower switch on HIGH, & for 300 miles the A/C worked perfect.
So my question is. Is the BLOWER SWITCH bad or is there a relay,switch, or anything else between the BLOWER SWITCH & Turning on the condensing fans???
I'm guessing the FAN SWITCH is bad just wanting to confirm before I go buy a $45 switch.
Thanks in advance.

 

I am not familiar with the 90 model civics, but I know in my 97 there is a resistor type device behind the glove box that allows the fan to work on 4-3-2-1 and when it is bad only 4 will work. But if you are saying those settings work but just are not cold then I would move on to test the AC relays and fan switch. Sorry I am not sure where it is located on your car but I am sure you can find a map of it somewhere and then just check for appropriate voltages as compared to a common or ground (chassis) along the circuit path the AC controls follow. Then replace parts not putting out proper voltage.

I would have to say it is strange that only one setting works. Sounds like it could be a switch or relay controlling the condenser fan. Also check the AC system pressure, they sell do it yourself cans at any local auto part store these days.

 

The blower switch enables the whole A/C system, the light above the A/C button and the condenser fans will not come on. If the light and the condenser fans go on/off when you press and release the button, but the compressor does not engage, the problem is probably the compressor clutch gap. With the gap too large, the compressor will not engage reliably especially after it gets hot. The gap can be reduced by removing the clutch plate from the compressor and taking out some of the shim washers that are on the shaft behind it.

It may have worked more consistently with the switch on high because running the blower on high in hot weather, the compressor might never cycle off and have to re-engage.

 

Thanks for the response. The A/C works perfect on High Fan It cycles & sometimes it works on Low fan but it appears that it the condenser fans will not work on low fan a fair amount of time. But on High 3-4 it works fine.
With the button on nothing works until you turn on the blower fan. Does the 90 have that resistor also.
If the Clutch was too wide a gap that would affect it in an position I would think. But I ran the A/C for 5 hours & made a few stops for lunch & gas. Every time I restarted the car the A/C cooled right down as long as I had it on high fan. Last year I gauged up the system (R12) & charged it. I don't think the A/C had ever been touched because my mom never used it from day one the only time it was used was when I drove it.It took a few ounces of freon because it was low. My sight glass is clear when A/C is running.
Thanks.

 

Does the light over the A/C button come on? Any time the key is on, button is pressed, and fan switch on any speed except off, the light should be on.

 

OK, now we are on the right track thanks to your question.
I went out since the sun is down seeing lights are much easier. I turned on the key to the on position just before the start. I pushed in the button in the blue light is out. Turn the fan switch on to any position blue light lights up & the fans come on. As I was fooling around all of a sudden on #1 LOW the light goes out & so do the fans. I mess with the fan switch & on everything goes. Then I move it to #4 HIGH & I see the blue light & fans go off then back on. So for what ever reason the Fan switch works sometime & some times it doesn't. in every position it is appearing. If you move the fan switch a little things come on or I guess go off.
So I think we are back to my original question is it the switch or is there a resistor some place in between that is bad?
Or is the resistor in the switch on this year & model?
Thanks.

 

I think the switch has a separate circuit just to enable A/C, it doesn't involve the resistor like some cars do. If the fan always works on all speeds the resistor is OK anyway. The resistor is separate. Sounds like your switch is bad.

 

The fan works on all speeds. That is what I thought. After all a 22 year old switch that has been used every winter for heat just might be wore out. I just didn't want to go buy a $45 switch if it might be something else.
Thanks MK378 for you help on this. I'll report back after I change the switch.
Thanks again