Electrical issues

[88olds32]

This is a little confusing to write up, but here it goes. The brake lights work when I press on the brake pedal. At night when I turn on the headlights, the headlights turn on, but the tail lights (which is in the same housing as the brake lights) don't turn on. The license plate lights won't turn on either when the headlights are activated. The weird thing is, when I activate the alarm, the license plate lights will flash. The front bumper marker lights won't turn on when I flip the switch, but will flash when I activate the alarm.

In addition to the above, the speedometer lights don't work either.

I've replaced every bulb and have checked various fuses.

Any thoughts anyone?

 

[AD8]

I'm having the exact same problem. The person I bought my 88 cutlass from tapped into the headlights and wired them to the tail lights. (found out when I started removing speaker wire from lights) Not sure what to do yet but I'm checking all wires first.