1987 Volvo 740 overdrive

Transmission problem
1987 Volvo 740 4 cyl Two Wheel Drive Automatic

my car just started having an overdrive upshift problem. I can start the car and start driving and the overdrive will not engage and then all of a sudden it will. Then when I pull to a stop for any reason it may or may not shift back into the overdrive gear once I am back up to cruise speed. Also the overdrive indicator light in the dash comes on for no reason while I am driving indicating that the overdrive is off but I am cruising in overdrive. I have had it shift out of overdrive while I was cruising and was unable to get it to go back into overdrive. Overdrive just has a mind of its own only working when it wants to. I haven't been able to find a common symtom to go off of to fix it. I have been having a problem with the electrical cuircuts as well. When I turn on the head light switch, all the gauges and dash lights go out and the high beam indicator operate reverse. Low beam lights the hi beam indicator light is on. Then after driving a while the dash lights come on and all the gauges come alive and the hi beam indicator works properly. Could this electrical problem be bleeding over into the overdrive problem as well?