2001 Honda Civic Multiple Mystery Problems

I have 2001 Honda Civic with about 126K miles on it. Recently it’s had multiple issues I can’t figure out…

  1. Most recent: fans stopped working. nothing happened - one day fine, the next gone, nothing. This is the blower inside the car.
  2. About a month ago, check engine light came on had it checked out and the mechanic said “it’s the thermostat but we can’t know what’s wrong until we get in there” that would be a couple hundred dollars. Since I wasn’t actually having any problems at all I let it be. About that time there was a seatbelt recall so got that taken care of (probably unrelated). The temp gauge looks normal.
  3. Electrical locks have been playing musical chairs for a while. When I lock the car I have to check all four doors - invariably one of them is unlocked which then lock manually.

I should mention as soon as I bought the car (7 years and 60 thousand miles ago) I had to replace something having to do with the AC, the condenser? It ran me about 1200 whatever it was.

I’m wondering, are these things related? a lot of electrical stuff? seems that the fans working would be the first thing to get fixed? how much should this cost me? or the thermostat?

You’ve had this car for 7 years, so.

How long has it been since the battery was replaced. They normally only last about 4 years.

The locks playing musical chairs could be a failing battery or a poor connection at the battery.
If the battery is not close to 4 years old, I’d remove the battery cables, clean the posts and terminals and reinstall them after coating everything with dielectric grease.
Also follow both cables and make sure the connections are tight at the other end too.
You didn’t say that the bettery went dead at some point and you needed a charge or jump, so I doubt that it’s the charging system.
See if that doesn’t cure the lock problem.

Fan not working;
I’d check the fuse for the heater fan. If that is ok you may have a bad blower motor, blower motor resistor, or the switch may be bad. I’d follow the fan leads…where they plug into the harness and check for voltage there first. If you have voltage at the harness (with the key on and the fan switched on, then you need a new blower motor.

What made the mechanic think there was a problem with the thermostat???

Check the blower motor at all fan speeds. If it works on the highest speed but none of the others, then it is either the fan or the fuse. If the fuse is good, tap the bottom of the fan and see if it starts running, if it does, then its the brushes in the fan, but you still have to replace the whole fan.

The fan is located behind the glove box and is easy to get at and usually not too hard to replace. It is not unusual for a fan to go out at this age/miles.

Without the actual code, but based on your description, I’d guess that the issue with your thermostat is that the coolant is not warming up in the correct time allotted. This is because the thermostat is not closing all the way when cold. This will get worse over time and eventually, the engine won’t warm up at all.

I don’t know why the mechanic made the statement he did. Maybe he is planning on gouging you by removing the thermostat housing and then claiming that he has found a lot of other stuff. Unless this mechanic has a very good reputation, I’d find another mechanic, this is a very simple and straightforward repair. The thermostat itself is only about $15-20, but the cooling system has to be drained and new coolant put in, so the cost can be higher than you would expect. Sometimes the hose has to be replaced as well, that would be the only unexpected that I would expect.

If the same door is always unlocked, then the lock mechanism in that door may have to be replaced, if it is random doors, then I’d suspect the master controller in the drivers side door, about a $200 repair. Honda has a history with these, but the symptoms usually involve random pulling of some/all the lock solenoids when they are already locked. Your symptom is different.

Thank you Yosemite & Keith :slight_smile:

I replaced the battery about 4 years ago so it’s time - that could be it.

When I was at the dealer getting the recall done I mentioned the check engine and they checked - said it was the thermostat but I just called to make sure and they said it was:

Code P1486 cooling system

So are the fans/blower not working likely to be related to this?

Blower does not work at ANY speed.

Any thoughts based on new info?

Thanks !!!


no they are not related.

I’d still bet on a fuse or the blower motor is shot.

I had one that blew the fuse twice, though it would blow good for a few days until it blew another fuse.
I pulled the blower motor and you could feel the drag when you tried to spin it with your fingers.
I replaced it and two years later and it is still blowing strong.

So even if you replace the fuse and it works, that’s just telling you that there is a fault somewhere that blew the fuse. If the fan is shot the fuse will blow again, even if it does start working.

I reread your post and I think the thermostat replacement is your main concern besides the old battery. If the thermostat fails and you overheat the engine, it could be a costly replacement of a new engine. Approx cost…$2000+.
I’d make an appointment, have them replace the thermostat and the battery.
At that time they can also check the blower problem out.

Thermostats are cheap $15 and a new battery will be around $100 plus the labor. Add a new blower moter $100 . At a good independent shop the total should be about $400 parts and labor for this car.

To see if the blower motor is okay you can run 12 volt power directly to the motor connections. If that checks out then check to see if 12 volts is getting to the motor while the motor should be running. If you have voltage there then the troulbe is most likely with the speed resistor pack. It is usually on the return side of the circuit. If there is no power to the motor and the fuse is okay then suspect the blower relay or the socket connector to it as the cause of the trouble.

Replacing the thermostat should hopefully get the cooling fans working again if they are having trouble also.

The lock trouble is most likely due to faulty wires in the door jam. They can break after time due to stress on them. After about 10 years things like this happen with cars. If you want to keep the car you would be wise to purchase the factory wiring manual for it to help you fix things like this. Ebay is a good source for them.