Brake lights on 98 Honda Civic not working

I recently bought a 1998 Honda Civic DX and discovered that my brake lights are not working.
I began troubleshooting the problem by first replacing the brake light
switch (under the brake pedal) which didn't help and then replaced the third brake light bulb (which was burnt out) but that didn't help either.
I then started looking at the brake light bulbs and discovered something a little odd. The actual brake light bulb has two filaments in it - the first is for the running lights and the second gets illuminated when the brake pedal is pressed. What's happening with my car is that if the headlights are on, both filaments are lit for some unknown reason. I should add that the turn signals still work so I know that there is power in the circuit.
Any ideas or suggestions on where I should look to fix the problem?
Thanks in advance, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You have a grounding issue. Both filaments are on when the running lights are on because the running light filament is getting grounded through the other filament.
Fix the ground issue and both should work as they should.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sorry about the multi-post.
Are there any known trouble spots for grounding issues in these cars or could it pretty much be anywhere in the circuit?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I can't speak specifically to that car, but usually the issue will be somewhere near the lights in question. Any rust back there? Start at the socket and trace the ground wire to it's destination, or run a fresh ground.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
..

It turns out the majority of the problem was caused by the brake/horn fuse being blown (the one under the hood).
The reason I said "majority" of the problem is that the third brake light and the two outer ones work now. The ones in the trunk are still acting up but at least I have functional brake lights again.
Thanks to everyone who replied.
Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Bet there is corrosion in the sockets or connectors.
--
Tegger

The Unofficial Honda/Acura FAQ
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tegger4/4/08 16:00Xns9A76A2683C2ABtegger@207.14.116.130

Check the simple things first. Does it have the correct bulb? Do this first. Check the contacts inside the bulb holder. When does each one get power? Use a test light or multimeter to do this. Get somebody to work the brake pedal for you. Is there corrosion anywhere? Did somebody try to wire up a trailer and botch the job? If you can read schematics, Honda puts out an electrical troubleshooting manual for most of their cars. There are wiring diagrams which show which circuits share a ground and where that ground is located on the car.
--
Pickleman
snipped-for-privacy@roadyourpantsrunner.com
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.