Volvo: 1981 240 wagon, volvo 240 wagon, volvo 240

Question
My 1981 Volvo 240 wagon would not go into overdrive until I rerouted the ground in the dash. I know a little about wiring, but not enough to fix it right. I bypassed the problem, but now I am able to put it into overdrive in any gear. How can I fix it right?

Answer
Hi,i assume that you have automatic transmission,there are usually only 2 problems in tis system,damaged wires beneath the shift level and the relay(below the glove compartment)
First to check are the wires from the small button on the gear change level,remove the cover and check those wires.