Volvo Repair: 94 volvo 850 non turbo wagon pnp switch, volvo 850, backup lights

Question
My backup lights are not working; get a flash as the shifter goes past the contacts. Volvospeed said it is the adjustment of the pnp switch. Please tell me where it is located. If it is on top of the tranny do I have to remove the air filter box? If so, please let me know any short cuts.
Thanks in advance for your help.

Answer
It would be best to replace the pnp but a volvo shop needs to get involved.  Its easier to adjust without the air box.  Its right on top of the trans.  there is the center nut and a bolt holding it in.  There is a line on the swith that needs to be centered on the shift post.  You should adjust this with the car in neutral.  This is the best I can explain it to you.  Roger