Again, a small problem in my 99 Camry: Fan switch for heater/AC appears to work only when the switch is set at the highest (4) position. If I set at lower ones, there is no air blowing in. It is difficult figure out what part went wrong. Perhaps, the switch itself has gone bad. Any input would be appreciated. Thanks. Hong
Hmmmmm....didn't we answer this already?
This could have 2 answers: both have common causes. I didn't think this would happen on a car this NEW, however: mine did it (on 3 cars!) with over 200,000 miles!
There is a resistance in the circuit that determines the speed. On my older Corollas, this was located in the fan assy, under the passenger's side of the dash. When you remove the fan (not for the faint of heart, BTW...since I am approaching 50 I think I'll start PAYING someone to do this!) youy can see the 'resistor farm', basically what looks like three springs mounted on a piece of printed circuit board. These 'springs' (resistors) are what determines the speed of the fan. If the circuit card looks burnt, or smells burnt, you *may* be able to repair it by soldering, but this is hit or miss. Best to throw it away and go to a junkyard. And if you're going to do this, maybe easier just to replace the whole fan.
On some cars, like my '85 Celica, the resistance is controlled by the switch itself. In this case, you'll probably have to replace the whole switch. I haven't had to do this...yet...
The other cause is the brushes inside the motor itself. This again requires removing the fan assembly and removing the cover to the fan. This has two phillips head screws and some tape that looks like electrical tape. Remove the tape, remove the screws, remove the circular fan from the other end and pull the (aw, I can never remember the names! Rotor?) assembly. Well, actually, before you do that, look at the top part of the motor. You'll see two black things making contact with the copper thingy (don't you love it when I get all technical?). They are on opposite sides of the rotor from each other. That is, if they are there! If they are severely worn down, what you'll see is a copper wire with a very small piece of carbon on it. These are (or were) the brushes. The brushes are what transfer electricity to the motor (sorry if I'm being too simplistic, I don't know what your expertise/experience level is!). If these are worn down to nubs, they need to be replaced. You can get a suitable replacement at any decent hardware store; look for motor brushes. They are about $3.00 each. Sure beats $120 for a new fan assembly from Toyota!
They also need to be soldered in. Before removing them, pay attention to the routing of the copper braid that attaches them to the piece of circuit card! Unsolder the old one, route the copper braid and solderer away. Note: this requires some patience!
Reassemble the whole mess (use a thin piece of stiff plastic to slip the brushes back in). You can also clean the stator and rotor with something like electronics cleaner, or even brake parts cleaner. Then you're going to do what I didn't do. You're going to put a drop of oil in the top part of the motor before you put it back together. You can also grease (very lightly) the copper pieces where the brushes contact. This will make it quieter when running.
If all this is too much work (it is frustrating to an extent!) just pull the fan assembly and take it to an electric motor repair shop. Should be about $20-30 to fix.
Good luck!
You can also grease (very
Agree with everything you said, except applying grease to the armature segments. There has to be a good electrical contact between the carbon-brushes and the armature. Brushes are self-lubricating to a large degree. On older British cars, the clutch throw-out bearing was often just a carbon ring which beared against the pressure-plate-pad.
And yeah,...at 50+ crawling around under/in a car is not the fun (was it ever?) it used to be!
Jason
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