your problem may be related to a bad noise reduction condenser. there is one located behind the trim on the left "C" pillar. that condensor is similar in function to the old condensors in the distributors with breaker points that were used to absorb electrical interference from the ignition system.
you will have to check with a Honda dealer to see if the "Noise Reduction Condenser" is available separately or if it is a part of the harness. as for the location, it should be to the top of the C Pillar above the point where the defroster grid connector is. it has a two pin white connector but the condensor is probably shrink wrapped around the harness.
the ground is also behind the C pillar trim.
hope that helps