1986 Volvo 240 DL overdrive wiring

[D Larson]

I recently had my car in a shop to fix the reverse lever
I suspect the wire to the overdrive was pinched and it caused the over drive relay to short out
The shop says this is not possible as the wire to the switch does not have a electricity in it. Another shop says the switch gets juice through the #11
fuse. Anyone know the truth.