Hi,
Does your Accord have the original alternator on it? If so it's
probably quite warn by this point. Typically a new alternator will
suply sufficient current for the entire electrical system, no matter
what RPM the car is at. However when they age, their output decreases
slowly to the point that it is noticable. When you are driving, the
alternator is spinning faster, which means it is capable of higher
current output. I bet if you installed a new alternator you would
notice a difference.

HTH,
-Jamie

SmarSquid wrote:
> '87 Honda Accord LXI Sedan (Automatic) with 200,000 miles. Still in
great
> shape and runs well.
>
> More of a curiosity item than anything else - when the engine is
running and
> the heater is blowing, the heater blows very strongly when
accelerating the
> engine, but drops down when idling. I haven't checked thoroughly to
see if
> other accessories are affected (interior or exterior lighting).
>
> Any ideas?