1994 Accord radiator fan won't come on

On my 1994 Accord EX (4 cylinder, 4 door) there are two fans; the AC
Condenser Fan (driver's side) and the Radiator Fan (passenger side).
Usually, my temperature gauge very seldom goes above midpoint (3 o'clock),
but most of my driving is open road country with very little city
stop-and-go. Lately, with hot summer weather, it seems that the AC Condenser
Fan is the only fan that comes on, and that my Radiator Fan never comes on.
The AC Condenser Fan comes on even when none of the console controls are
calling for Air Conditioning. And if I were to run the engine long enough
the temperature gauge needle would go up to HOT and indicate overheating,
without the Radiator Fan ever coming on.

Here is what I have checked:
1) The fuse for the Radiator Fan is good.
2) I checked the relay for the Radiator Fan by swapping it with the one for
the power windows (they are the same spec) and the power windows work
(before and after), so I believe the relay is not the cause of my radiator
fan problem.
3) I removed the radiator cap and let the engine idle for awhile. I did not
see any bubbles that might imply a bad head gasket (only 300,000 miles, so
far).
4) The radiator cap is rated for 13 lbs. It seems to be seating itself
properly. I believe that it must be holding some pressure, since sufficient
temperature is realized to cause the AC Condenser Fan to come on.

Here is what I would like to check:
1) I believe that my problem is either the ETC sensor, bad Radiator Fan
motor, or bad wiring. I would like to run 12V from the battery to the
Radiator Fan just to determine if the fan motor still good, but the wiring
seems to come out of the bottom of the shroud, and I can't access it from
the top. I tried to remove the whole Radiator Fan shroud, and I even
started to remove the whole radiator, thinking that would be an "easier"
approach, but I balked when it came to disconnecting all the small hoses. Is
there a simple way to hook up 12V to the Radiator Fan so I can determine if
it works? Also, when removing the radiator on a '94 Honda Accord how does
one access the bottom of the radiator so the electric to the Radiator Fan
and the assorted hoses can be disconnected?

Thanks,

Gary

 

On my '97 (which is the same series, and on my '90 the radiator fan
has a connector that is on the passenger side of the fan that can be
disconnected from the top by reaching down beside the radiator. May
be easier if you remove the radiator overflow tank. Disconnect the
connecter and then hit the two malel pins in the connector attached to
the rad motor with twelve volts. If it doesn't go it is no good,
probably brushes, but I haven't found any replacements. have to
replace the whole motor.

You can get the fan off from the top by removing the screws that hold
it to the radiator, pushing the AC pressure line back (it has a
bracket, remove it) then finagle the thing out. I did it on both my
vehicles.

Good luck,


Frank

 

-------------------------------------

Before you start goofing around with hardware, fill the reservoir to MAX
three mornings in a row. I'm guessing you have air in your system, and
the sensors won't turn on the fan unless they are swimming in coolant.
Any chance I'm right? Let us know if you find it 'sips' coolant each
night.

'Curly'

 

On my 1994 Accord EX (4 cylinder, 4 door) there are two fans; the AC

Frank-
Thanks for tip on removing the overflow tank. There was just enough room to
stick my arm down there and disconnect the connector. I removed the entire
fan motor
with shroud and tried to fire it up with my battery charger. Initially, upon
connecting
12V to the two male pins, I got no response from the fan. But after further
attempts, somehow
I was able to get the fan to spin. I figured it might have something to do
with corrosion
that I saw on the connector, so I cut up one of my my wife's fingernail
files and used it
to clean up the pins. Upon reconnecting the pins to a 12V source I was
getting an
intermittent response that was definitely more related to my picking up the
whole fan assembly
and rotating it on it's axis, and totally unrelated to my initial concern
about corrosion of the pins.
It would work perfectly with the fan in one position, but wouldn't spin at
all when turned
90 degrees. It was not related to the wire that runs to the fan. It was more
like worn out brushes,
as you suggested. I have seen this same thing with power hand tools like
drills.

Is it possible to just buy a new motor without the shroud and fan?

Gary

 

Curly-

Good thought. Actually, I keep my reservoir tank filled on the high side and
monitor
it whenever I check the oil. I had "just one" incident a couple of weeks ago
on a
particularly hot day when it "sipped" a little. But, it didn't "sip" a
little each night. I
probably had the reservoir filled too high, and there was some overflow. Now
that
I know the radiator fan was failing I think that the sip was related to
that. But with
300K on this vehicle, there could easily be more than one problem. I will
still keep
my eye on the reservoir tank level. Thanks.

Gary

 

Yes.... I bought a motor for my civic. Disassembly is simple. Just make
sure the new motor has the same shaft as the original for the fan
blade.

 

Gary Kaucher wrote:
.. . . . . I removed the entire fan motor with shroud and tried to fire
it up with my battery charger. Initially, upon connecting 12V to the two
male pins, I got no response from the fan. But after further attempts,
somehow I was able to get the fan to spin.

----------------------------

Most modern battery chargers won't put out any current unless they
detect a partially charged battery on their circuit. They won't charge a
totally dead battery, and they just act 'dead' if you hook a voltmeter
to them to see why they're doing nothing.

I use a small 12 Volt alarm system battery for testing such things,
since it's small and can't put out a thousand amps if something gets
shorted. Great for car stereos on the bench too.

Murphy was right.

'Curly'

 

Gary,

Intermittant running is more than likely worn brushes. They are worn
to the end of there service length and when you bump the motor you get
them to temporarily engage the commutator.

I found a motor for my 97 radiator fan. I could not find one for the
other fan (the AC, drivers side) fan, and had to buy the whole
assembly. I can't remember where, but it was at one of the national
chains (Advance auto, Oreilley's?)

After taking it apart (the old motor) I confirmed it was the brushes.
However, I couldn't find a set to fit and they were not designed to be
replaced but could be if you could make or find a set of that size.

Frank

 

Great thread here.

BTW, carbon brushes are very soft. You can buy oversize and sand down to
fit. Solder in and go. Even works for alternators.

 

Yes, I saved the old motor. I'm going to play with it and try to buy
some brushes that are close and see if I can shave then down and get
it going. I'll have one in reserve since it fits either vehicle and I
haven't had to change the 90 yet. When I get time and while I'm doing
it and if it works I may take some pictures and see about putting it
on the site you maintain.

Problem with a fix like this for me is I rarely have time to avoid
buying a part and making a quick fix. Any repair that requires
thought, research and fabrication usually takes too long. Both these
old Hondas are away at college and they generally limp in for me to
make a quick fix and are gone in a flash. :~)

But hopefull, what I've learned may help someone else.

Frank

 

Frank-

I opened up the motor and the brushes were both "used up"
as far as they could go, with one side worn slightly further from
the armature than the other. Looking back, this seems to make sense now.
The last time that I noticed that this radiator fan was working properly,
was after I did a slow 15 hour overnight charge on my battery. I'll bet
that the fully charged battery had enough juice to overcome the distance
between the worn out brushes and the armature, allowing the fan to turn.
So, if your radiator fan only works immediately after charging your
battery to the max, there might be a good chance that the brushes are
worn out.

I found a new motor on eBay for $36 (shipping included) and I'll pop it in
when it gets here. Thanks for sharing your insight. It was a big help.

Gary

 

Gary, I just replaced the motor on my AC fan (95 Accord) I don't know
if the radiator FAN and AC FAN are installed the same way but I would
guess that they are. Anyway,
the AC FAN as a 10mm nut that secures the fan to the shaft, under the
fan there is a washer that sits on top of the motor shaft. I made a BIG
mistake when I put the fan on the new motor. I put the fan on the
shaft, then the washer, then the 10mm nut.

Reinstalled it on the car and the motor went up in smoke! Luckily the
Honda dealership exchanged for me ONLY because the company that I work
for does a lot of business with them. Normally there is NO exchange or
refunds on electrical parts.

So just make sure you put that washer (if it has one) underneath the
fan and not on top. And make sure the blade turns freely. If the washer
isn't installed under the fan when you tighten down the nut the fan
blade will not turn.

 

Gary, I just replaced the motor on my AC fan (95 Accord) I don't know
if the radiator FAN and AC FAN are installed the same way but I would
guess that they are. Anyway,
the AC FAN as a 10mm nut that secures the fan to the shaft, under the
fan there is a washer that sits on top of the motor shaft. I made a BIG
mistake when I put the fan on the new motor. I put the fan on the
shaft, then the washer, then the 10mm nut.

Reinstalled it on the car and the motor went up in smoke! Luckily the
Honda dealership exchanged for me ONLY because the company that I work
for does a lot of business with them. Normally there is NO exchange or
refunds on electrical parts.

So just make sure you put that washer (if it has one) underneath the
fan and not on top. And make sure the blade turns freely. If the washer
isn't installed under the fan when you tighten down the nut the fan
blade will not turn.


Not sure, but I don't think there was such a washer on the radiator fan. I
had to
slip the fan over a rectangular "key" on the motor and screw it on. Thanks
for the
heads up.