Hey guys, first post on the forums and new member here. I recently bought an 86 Sport model and I noticed that when I turn the radio on, a heartbeat like noise plays through the speakers and the door ajar light blinks on and off. Anyone know what is causing this to happen?

 

The heartbeat sound could be caused by a missing condenser (capacitor). I can't speak for second gens , but on a first gen RX-7 the condenser is located on the top trans inspection plate.

 

The door light has a simple sensor/switch at the bottom of the door. When the door is open it sends a ground to the warning light system which causes the light to turn on. Problem could be the switch or it could be the warning light system itself as it is prone to cold solder joints. The wire for the switch at the dash might also be making poor contact w/the warning system causing it to flutter. The wire color is Blue/White.