I recently bought a 1994 concours, 4.6 engine, and I've never been happier. In fact, I'm so into this car that I want everything to work perfectly. The only problem I'm noticing is that all my lights pulse. The green speedo and radio display aren't noticeable, but the rest are. Also, the passenger side tail light blinks top light, then bottom light, back and forth (up and down, technically). The little two light display in the back window is dim on that side, and gets dim when the turn signals on, and cuts out when I brake. All the bulbs are good, I think... I'm used to old cars, so I'm completely lost on this, whether its wiring or a ground or alternator... nothing else is affected. Are these problems linked? Any ideas are appreciated!

The taillight issue is probably a corroded socket for the bulb that quits with foot on brake. The pulsating lights could be a faultly ground (dirty, loose) Verify engine to frame grounds are clean and tight. Verify alternator working to capacity. Take off battery ground cable, clean cable and battery connection surface. To check taillight bulbs, put the four way emercency flashers on, then walk around car to verify ALL lights blink the same. The socket replacement is no different than an old car. Just verify its a socket not just a faulty bulb.

is there any way to check the alternator without removing it? looks like a pain to get out... if not, i'll bite the bullet.

I have a 1998 concours my lights where doing the same,changed the alternator and the pulsating stopped.
It came out from the bottom,check the forum on removing, it was easy....Good luck!

The only proper way to check an alternator is on the car. Many shops for a small fee can load test the battery as well as the alt. in a matter of minutes. Again, pulsating lights can be a poor ground as well so rule that out first.

Had this issue years ago on a '72 Impala. The cause was a loose connection of the main cable to the solenoid.
FWIW
YMMV