Volvo Repair: 1992 volvo 240 issues, bulb failure, center vents

Question
#1.  All my tailights and brakelights work properly but  my bulb failure light still comes on and off.

#2  I can't tell if my electronic overdrive is working. How can you tell if the relay is bad.

#3  It sounds like a fan is running constantly when I am highway driving<  

Answer
1. the problem could be a corrosion problem,2 different type bulbs can cause it.the corrosion could be on the connector to the light or on the bulb socket holders or circuitboard.

2. you would need to check it with a test light to see if it is getting power into and out of it.it is located behind the glovebox which will need to be removed to see it.it will be near the center vents it is a white relay.

3. without being able to see it I can not say what that may be.