Fuelie777

1995 Honda Civic, 1.5 L Engine. A/C has been intermittent, probably a few issues. Symptoms: blower fan intermittent. 20 Amp fuse to compressor clutch & condenser fan continues to blow. (Note: I have factory manual).

What has been done: Checked blower with separate 12 volt source, working fine. Checked relays, all operational. Removed control head from dash (a pain) changed out fan control switch, changed out resistor pack, when initiall installed, blower worked find from ignition on. Started car, turned on the A/C switch, blower fan will not come on and the 20 amp fuse blows. I see in the circuitry the A/C thermostat and the mode control switch comes to play. Looking for further suggestions?

sumdewd

Welcome to HT!

Any recent work done to the car? Does the fuse blow randomly or immediately? Did you use all new parts, especially the blower resistor pack? Any wires or connectors appear to be cooked or brown? Does the blower motor restart if you kick the blower housing (under the passenger dash)?

In my experience this was due to a faulty field coil in the compressor clutch. It randomly blew fuses then it would always blow them. Then the compressor clutch's field coil insulation failed and it shorted out. I literally saw the bare wiring when I removed it. New field coil and I was all set.

We might need more info though on your situation. Sometimes the blower motors start to use more current than they're supposed to and they just need to be replaced.

Fuelie777

The recent work was spark plug replacement, cap & rotor, fuel filter. The A/C stop working about a year ago, I started with the trouble shooting in the manual. I ended up replacing the blower, the resistor pack, and the blower switch (in the heater control box) with all new parts. None of the wires look cooked or brown, they all were actually in great shape, so I believe those components were good. The blower motor works with a separate DC source applied (pulled out and connected with a battery). When initially installed the parts, turned the ignition on, and the blower was working correctly. Started the engine, engaged the A/C the fuse immediately blew. You might be correct in that compressor clutch's field coil insulation had failed. Never thought about it. I also now remember when my son had it out on an errand, the condenser fan was operating, probably due to the engine coolant at temperature and at idle. the compressor coil is a pain to get to but will need to remove the front bumper and look at it.

Any other suggestions to look at would be great and this a head scratcher. Thanks.

Jon Petersen

Hey man, I have somewhat of a similar problem, I wanted to ask for your help. How in the world did you get the heater control panel out? Like, what tools did you use? I tried getting it out and it looks like I'll need some crazy angled screwdrivers and maybe a robotic hand to get that out.

Since the fuse blows, I'd imagine it's a compressor problem. My fuse doesn't blow, it just turns off sometimes, turns on sometimes seemingly randomly. What I can do to get mine to work is to ground out the evaporator thermostat blue/red wire, which forces the compressor and condenser fan to engage, making the air cold.

Fuelie777

After you get the front portion underneath the radio, off, (four screws). Then you need to remove the radio. A few screws that are easy to remove. The antenna connector and radio connector is next. Remove the radio. Then the pita. You take a phillips head drill bit and cut it about 1/3 of the length. I believe it will fit into a 5/32 quarter drive socket. Use quarter drive wrench with this off and you can get the far right and left screws out. There is one in the back that goes into plastic. Easy to get to. Now, removing the two connectors to the heater A/C control panel is hard, but you stick your fingers in there and feel for the latch on both and then wrestle them off (need strong hands). I would take a picture of the cable to the hot/cold valve so you can see how it goes together, and it must come off (actually do this first and you have some more room to work the two connectors). That is how I did it.

You may be correct about the compressor and clutch. Right now, I also need to get the blower motor working. It should work independent like a heater. It also blows across the evaporator for the AC. If you have any further observations, it would help.

Jon Petersen

I don't get it. Can you explain that again, maybe differently? I can't really picture what you're saying.

Fuelie777

Sorry, Will try to explain. Just in front of the shifter there is a panel with the ashtray and cigarette lighter. Four Screws two on either side. You might have to move the shifter to remove the panel, there will be a connector for the cigarette lighter.

The Radio comes out next. Can't remember two or up to four screws. It will start to slide forward, remove its connector and antenna wire. It then slips out. Really a piece of cake

Now to the hard part. There is a cable which controls the hot/cold valve from the panel snaking down and through to under the front passenger side. I recommend to remove the glove compartment (two screws). You will have better access. See how it attaches, take a picture with your phone so you can see how it is situated for re installation. remove that cable connection from the valve. Then there are three screws for the heater control panel. One in the back (phillips head) that is easy to see and to reach. The other two are up front slightly behind the front dash panel. I took a phillips head driver used on electric drills and cut it to 3/4" to 1" long. You can use a small 1/4 drive ratchet and a small socket (mine was 5/32 or 3/16 hex) and you can then reach in there and loosen the screws. Take the screws out. The far two screws that go through a plastic piece into a sheet metal clip on the heater control panel. Move the heater control panel out and disconnect the two connectors. This might be hard so be very patient and they will come off. Then the heater control head comes out. Installation is the reverse. I changed out the fan control switch and checked the other switches. Hopes that helps.

mk378

There really isn't much connection between the two parts of the system. The fan switch only controls a small current to pull in the condenser fan relay if the fan is turned to speed other than off, the A/C button is pressed and the thermostat is warm.

If you do not press the A/C button, will the blower always work? If not, resolve that first.

The blower not working though will not blow the compressor / condenser fan fuse. That fuse would only blow if one of those two parts draws too much current, or there is a short under the hood. The condenser fan should spin freely by hand. The resistance of the clutch coil should be 3 to 4 ohms to ground. If less than 3 ohms, the coil is bad and it's going to blow fuses. Also look for frayed wires where the wires go under the pulley on the compressor.

All this is assuming the wiring is stock. Check for modifications by some previous owner.

holmesnmanny

as a previous poster suggested, it's likely the clutch coil is bad and is shorting out the fuse, disconnect the clutch coil connector and turn on the ac and see if the fuse blows

Fuelie777

Thanks for the input. this weekend I will check the coil resistance, and also disconnect it. I will also check the condenser fan as I cannot attest that it is moving freely. I also need to resolve the blower not working. I have a new fan, as I have checked independently that the old one was working, but maybe it drew to much current and blew out the new resistor pack, I need to measure the old one and then the newer one. The blower one is very perplexing as it is tied to the A/C temperature thermostat and the mode control motor driver circuitry. The car was my sister's, was new when she bought it, no modifications.

any other suggestions about the blower would be appreciated. Thank.

mk378

The resistor depends on airflow from the blower to stay cool and not burn out. When you have the blower out, check the duct for a mouse nest or other obstruction.

Though the A/C is connected to the blower switch, it is a separate low-power circuit that only serves to turn off the A/C if the switch is off. It is not going to cause damage to the resistor or motor.

Fuelie777

mk378. Thanks for the insight. Makes a lot of sense.