When your lights go bright and the fan speeds up etc. that means the
voltage has gone up above normal.
First thing I would do is check the voltage. Put a voltmeter on the
battery terminals. A fully charged battery should show 12.7 volts. Now
turn the engine on and read the voltage on the battery terminals. It
should now read about 13.7 volts. Have someone change the speed on the
engine and watch the voltmeter....if the alternator is good it should
not change voltage.
Alternators produce an alternating current(AC), have a rectifer
circuit in them to produce a DC current and a built-in regulator to
give a 13.7 volt DC output.
I am going to guess you have a bad alternator.

Find a mechanic that understands electrical, not all mechanics
understand electrical problems.

I looked a 1990 "Accord" wiring diagram and it shows two wires from
the alternator to the "engine control module'. I have no idea what
that is for.

Cheers, Charlie


On 26 Dec 2003 16:13:33 -0800, xbiggwbx@aol.com (Wayne) wrote:

>Hello!
>I own a 1990 Honda Civic, 4-door/4 cylinder car. When driving, I
>noticed that my headlights and dash board lights get very bright, and
>then dims back to normal. At the same time this happens, my defroster
>fan motor, speeds up and then slows down to normal in conjuction with
>the headlight and dashboard lights.
>
>I also notice that my battery light on my dash board flickers on and
>off occasionally apart form the dash board lights.
>
>
>Oh by the way,
>
>My alternator was replaced March of 2003. Prior to changing my
>alternator, my battery light constantly stayed on.
>
>My mechanic recently checked my fan belt and told me that it was o.k.
>
>Does anyone have a solution to what this problem might be?
>
>
>Please email me: xbiggwbx@aol.com