Hello, I've got a 2000 civic EX, with bit of two problems. The first being no heater fan function. Now I've searched this and some other Civic forums for solutions, but none really seem to address the issues with these problems.

I have replaced the heater fan,
resistor box,
motor relay,
7.5a fuse,(which wasn't blown),
Have jumped the fan, (old/new) and they work off the batt.
The wire harness appears to be in good shape, no breaks or worn areas exposing bare wire, though whomever had the car before did some really nutty wiring with the stereo. The fan worked prior to 4 days ago, when it just quit. As well it worked for a few min until I turned up the fan ****, then it quit.
When I turn on the fan switch I just get a click. When I turn the position, and hot cold switch, I can hear the actuators moving, but still no fan.

Yes before, and by now, I'm thinking it's the fan switch, but I'm not sure how. You see the previous owner left another control unit in the car, and I took it apart, it was as I thought. The fan switch gets power from the other two plugs, while the plug that fits behind the fan switch itself goes to the Ac/rec/def buttons, which work just fine. So I'm trying to figure out how the switch goes bad. No burnt wires or parts that I could see, but is the circuit board prone to problems? A replacement is on the way, and I've done what Chilton's documents, as well as what I've found on forums. If anyone can shed some further light I'd appreciate it, before I go bringing it in and spend money I don't have.

Second issue is the left front speakers, A tweeter, and the 6.5 in the doors do not work. No breaks in the wire, but I'm not sure about the wire behind the fender from the grommet. The reason I included this with the fan problem ,is i was just connecting the speakers when after the fan quit. No arcs no shorts,blown fuses. I can't see how that would affect the fan, judging from the wiring diagram. They're separate harnesses but again, there was some wild S$%t going on with the wiring before I removed/replaced the deck harness.

Again thanks for any help.

 

Unfortunately wiring is a real PITA.

If someone else did some crazy wiring stunts you may be looking at taking your dash apart to inspect and possibly redo the cabin harness.

The other thing I might suggest to you is to google Factory Service Manual (FSM) for your 2000 civic. You should be able to find a download of it. It should be a PDF file, don't do any install type program (EXE/COM). Either PDF or zip/rar of a PDF. The FSM is far superior to Chilton's or Hanes and can be had for free.

Wish I knew more to help.

 

Thanks for that, as Chiltons seems to be just the basics in this regard. I did check for broken wires etc, didn't see any, but there may be some somewhere. So don't exe the pdf? I'll try it. As far as the speakers go, I do plan to run them direct to the amp, just looking for a suitable place to drill in the door and behind the kick panel etc. I just wanted to get it working right if I could, to eliminate any factors and lingering issues. thanks again.

Up date: About an hr ago, I decided to go check on some things with this problem after looking through the FSM. When I turned on the power, the fan worked. I cycled through the speeds, and on/off. Started the car, and it was working correctly. Ten min later I thought too good to be true. I was right, didn't work as before. I'm thinking it's gotta be the switch or the board the switch is wired to. Possibly a bad solder/resistor that's shrinking because it's so cold here, and when it expands, a connection is broken. Got a new ctrl unit coming, but I'm trying to figure out what and why, besides how to fix it. Maybe, if I can figure this out it may be of some help to someone else. As I said, didn't really see too much detail about this on the forums/web search.

 

Update;
I've now replaced, Heater control unit, Wire harness for control unit, and the other heater relay directly on the blower motor itself. It worked for five minutes, and then quit. Now nothing. Everything is getting power, the resistor is clicking on and off, yet no blower motor function, thus no heat. I and a few others are at a loss. One last thing I'm going to try is to sand off the grounding point, as the bracket the harness is grounded to, is oxidized. Then is off to spend money I do not really have. As well I forgot to mention the radiator levels are good, and the flap doors work.

 

What is everything? Be specific about what you have tested for voltage. For example, can I assume that the blower motor connector gets battery voltage with the key in ON(II) and the blower switch off? There are a few electrical tests that can be done to pinpoint the problem. This is a better strategy than randomly replacing so many expensive parts. Do you have a multimeter?

Also check the G401 and G402 grounds.

I don't think the resistor/transistor clicks. Do you mean relay? If so, which one?

 

As for running the speakers without leaving holes in my car.

The stock harness that connects to my stereo plug and play one I cut the front speaker wires about 4 inches from the connector. Then I join 2 pieces of speaker wire directly to the stock wires and run it to the amp down the arm rest under the carpet.

I can reconnect back to stock easily.

 

Sorry for the lack of clarity. The blower mtr, gets power, there's power at both relay's, both under hood, and on the motor itself. Yes I have tested for voltage at the harness pins as the FSM you posted says. I'm not really sure what's clicking, but if that's the relay's function, then I miss-typed. It does so when the fan switch is turned on/off. Yes the grounds were my next go to before going to a shop. they appear to be good, but there's oxidation around them, so I was going to clean them off and re-attach. The parts I replaced were to cover bases. As well I did believe the harness was bad due to the fact that the main plug was getting power, while the harness that plugs in was not. The ground is in the main harness, so as per the FSM, I thought there may be a break in the wire.

As for the speaker situation, there would seem to be a problem in the harness,and or plug. With this issue unresolved, that part has taken a backseat.

Thank you for the help, and I'll let you know about the ground chk.

 

understood, I'm just trying to run them off the deck for now. The problem is there's no voltage at the stock harness. I was going to do what you did, but my preference is to run them directly off the amp. as i said above, I'm thinking there's a problem within the harness wiring itself, as the windows and locks work. Just not the speakers. Thank you for the help.

 

How is the deck wired then? Because the stock harness should also have power to tun the deck on.... If you connect the speakers directly to the amp and to the deck wires you won't be able to use rca cables to the deck. It will send double signal and send the amp in protect mode.

I think you need to rewire that cabin... I have some mixed up crap on mine too.. Who ever did my car put the left wires on the right and the right on the left but everything works.

 

No I'm just trying to get the stock wiring to work for now. I was going to either wire directly or do what you suggested. Right now the deck is wired to the harness through a wire harness. plug-n-play. So not getting any sound from the front left may mean there's a wire issue. I did take out the old deck,(the left side didn't work when I bought the car), and it was a mess. It's all removed and replaced, and everything else works except this.

 

yup. trace it from the speaker all the way through the door hose.. wires in that always stretch and pop over time..

 

Try this test:

1. Unplug the 20P connector B at the rear of the heater control panel.
2. Turn key to ON(II).
3. Ground the Orn/Wht wire in the 20P connector B (pin 13 in diagram) to the metal frame under the dash.
4. Does the blower run at full speed?

The ground wire is easily tested with a multimeter. No need to guess. Do you know how to do the test? If not, I can give you instructions.

 

No, that would be helpful. The G401 G402 grounds, are at the kick panels according to this diagram? I thought the harness ground was the one directly behind the console on the frame since the wires for the blower trace back through the harness. Just need some clarity. I'm going to run these tests tomorrow, I'll check here for your instructions before I do.

 

The only grounds for the blower and heater control panel are G401 and G402.

Does your multimeter have a continuity test function? Or does it just measure resistance (Ohms)?

 

Yes it does have continuity function as well as ohms It's the Extech mn36 model. As for the grounds, I'm looking for the location. Is it in the pins? or is it bolted somewhere close by?

 

See diagram in post #12.

Ground wire tests:

Unplug connector A at rear of heater control panel.

Test whether connector A pin 6 has continuity to body ground. Use the metal frame under dash as ground.

Do the same test on the Blk wire pin in the unplugged blower motor high relay connector.

 

No the fan doesn't work with the orange/white wire directly grounded.

 

With the key in ON(II), what voltage to body ground do you measure at the orange/white wire terminal in unplugged heater control panel connector B?

With the key in ON(II), what voltage to body ground do you measure at the Blk/Yel wire terminal in the unplugged blower motor high relay connector?

 

At orange/wht 12.22v at blk/yel 12.33v

 

1. Unplug the blower motor high relay connector.
2. Turn the key in ON(II).
3. Ground the Blu/Blk wire terminal in the unplugged blower motor high relay connector to the metal frame under the dash.
4. Does the Blower motor run?

 

No. Don't hear whatever is clicking either.

 

The clicking was the blower motor high relay, which the test bypassed.

Verify that the blower motor gets battery voltage.

1. Unplug the 2P blower motor connector and turn the key to ON(II).
2. Measure voltage to body ground at the Blu/Wht wire terminal.
3. What's the reading?

 

At the blower motor pin 12.31v.

 

Did you piggyback power off of the a/c controls for the head unit?

 

At this point, your tests suggest that the Blu/Blk wire is broken somewhere between the blower motor connector and the blower motor high relay connector.

You can verify by continuity testing the Blu/Blk wire between those two points.

1. Turn key off.
2. Ground the Blu/Blk wire terminal in the unplugged blower motor high relay connector.
3. Set multimeter to read continuity.
4. Test continuity to body ground at the Blu/Blk wire terminal in the unplugged blower motor connector.
5. Is continuity detected?