My '87 Horizon's (Plymouth's Omni) back-up lights only come on when I'm holding the shifter (auto trans) right between Reverse and Neutral. If I have it in Reverse just normally they won't come on. I don't know how to go about fixing this, but it's really annoying/dangerous.

Also, my tach sticks at either just above 1000 RPM or just under 2000 RPM most of the time. Sometimes after I've been driving for awhile it unsticks, but might freeze again later. I don't see any rhyme or reason for it and would like to make it work all the time.

Thanks.