Relay is under the dash to the left of the steering wheel, behind the
Cruise Control Module.
It's a MAIN RELAY, not some other type relay such as horn, cooling fan etc. etc.

The main relay is on the left side of the dashboard, very near where the
driver's knee is. More descriptions appear at:

http://www.markl.f9.co.uk/howto/electrical/main-relay/main-relay.htm

http://www3.telus.net/public/johnings/MainRelay.HTM

http://techauto.tripod.com/mainrelay.htm

What kind of research did you do? I just go to one of the many Honda online auto
parts sites and follow the pointers for my particular car. Any local honda parts
seller should be asking you the make of your car, too, as needed, to get the
correct relay. (Though for all I know this particular part may be the same for
many Hondas.) I think they all have the letters and numbers RZ- _ _ _ _. Various
numbers go in the _ _ _ _.

Try http://www.hondaautomotiveparts.com/auto/jsp/mws/catdisplay.jsp . Put in
your car's info, then choose "Fuse Box-Relay." The relay you want is item 28 for
your car.

If you're doing this yourself, it's often somewhat persnickety to get the whole
relay out, but rarely have I heard of anyone failing in the effort.

The other day someone posted here that, rather than removing the whole relay,
they left the relay case attached to the car and just pulled out its guts.

DaveT  ...I recently went through the same deal with my 89 Honda. I
came across this website complete with pics so that you know what
you're looking for.
http://www.markl.f9.co.uk/howto/electrical/main-relay/main-relay.htm

The part cost $60 at a Honda dealer, maybe less if you get an offbrand
from an autoparts chain store. I hope this helps.

DaveT,

 First off what you want to replace is the main relay. It's not easy
to get to but here is a website that I found useful.
http://www.markl.f9.co.uk/howto/electrical/main-relay/main-relay.htm

This website actually shows you how to solder and repair the relay
but I am not that handy. I just bought a new one at the Honda dealer
for $60 and replaced it. You may find an off brand cheaper at an
autoparts chain.

Here is a thread from the forum I used to find out what my problem
was.

http://www.trustmymechanic.com/forum/viewtopic.php?t=3110&highlight=main+relay

My main relay was located above and to the left of the fuse box. Sort
of on the outside wall and to the left of where my feet would be while
driving. It took some contorting and was not easy to get to.

Good Luck

http://www.markl.f9.co.uk/howto/electrical/main-relay/main-relay.htm

How to repair the relay.Also has pix on where the relay is.
(under the dash on the driver's side.)

 You know the relay is a problem or just assume?  From Hondas
of that period, there were a number of relays involved in
starting.  Including one that gets the fuel pump pumping for a
few seconds after ignition switch goes to an 'On' position;
regardless of whether the ignition switch goes from 'On' to
'Start'.

 In a Civic, when hot, one relay driven directly from the
microcontroller would sometimes not trip.  Never got the
chance to learn whether the controller was not outputting
sufficient current - whether controller transistor output
degraded in hotter weather.  But the question is whether you
specifically know it is that relay, or have just assumed.