SUB-FAN PROBLEMS with a '87 Honda Accord LX-i w/4-spd AT

My car has two fans, one that comes on while the car is running for cooling
and when the AC is on, the other, I am not sure (perhaps for additional
cooling?).

THE PROBLEM IS: When the car is turned off, the sub-fan to turn on
sporatically and stay on indefinitely and run the battery dead.

I have unplugged the fuse connected to this fan and it doesn't seem to
affect the operation of the car or any of its accessories, but I would still
like to find out what might be the problem. The Honda dealership doesn't
seem to know.

One other thing. When the AC is on, the engine will bog while idling
(whether the sub-fan is operational or not).

One more thing that might be related. Sometimes, while the car is in drive
(that's when it is most noticeable, but it does it in drive as well) the
engine will increase in laboring/bogging up to a certain point until it
comes out of it. To give you an example, it's like driving a manual and
releasing the clutch without giving it enough gas off the line, and then
just before you kill the engine, you press in the clutch and the engine
begins to run normally again.

One last thing that might be related. When you are idling in drive and have
the turn signal on, the engine will fluxuate to the rythm of the turn
signal. Is that related to the altenator (potential problem?), or is it
something else? It has done this for more than a couple years. Again, the
Honday dealership does not know what the problem might be.

If you have any experience or solutions to any of these problems, I would
love to find out and solve these seemingly minor issues.

 

First off, one fan is for your A/C condensor (for use while the A/C is on, it
turns on when needed as per a pressure sensor in the A/C system), and the
other is for your engine cooling system.

If the rad fan stays on all the time, it means that the relay is stuck, or
there is a lot of corrosion on the fan itself. As far as I know, it should
not turn on when the car is off, so I would start by finding and replacing
that relay. If that doesn't solve, then check the contacts on the fan to
ensure no corrosion is present.

As far as your car 'bogging down', not too sure what you mean. You have to
remember that this is only a 100 or so horsepower motor driving the A/C, my
dealer told me to expect up to a 20% decrease in performance when using the
A/C in hot weather on my 98 civic. It would definitely be more noticeable in
the city than on the highway.

If you feel that your performance decreases by more than 20%, I would check
to ensure that the system is not overcharged, or that the bearing in your
compressor is not shot.

A quick way to ensure that your electrical system is in good shape is to put
a multimeter on the battery while its running. It should be up around 13.5 -
14.5 volts. Any variation from this indicates a problem. When the car is
off, the voltage should not drop too far below 12 volts. If this doesn't
reveal a problem, then I would visit a good electrical shop to make sure
there are no shorts or other problems in your system.

t