Volvo Repair: 84 240 Manual Shift, phillips screws, overdrive switch

Question
My 240 wagon overdrive was "rewired" previous to my ownership and an overdrive switch moved to a spot above the stereo (no doubt to make room for the cool "8 ball" shifter)..  I can move along in 4th and click the the button, and it goes into overdrive fine, same with clicking the button again and having the trans come out of overdrive.  2 Questions..
1)  I have noticed no lights on the dash to indicate the overdrive being on or off, should I look for a burnt bulb or is it likely that the previous owner just wired the dash switch direct to the relay? Does the dash light work on a combo of vacuum and engine speed, or is it just a reminder indicator?  Shold I attempt to rewire this as it should be?
2) Does the overdrive automatically kick out at any time during shift or clutch action, or is it purely manual and could be engaged at all times in all gears?
Thank You! - Volvo Newbie :)


Answer
    YOU MUST NOT KEEP THIS CAR IN THE OD position..when you back -up ...chances are you may damage the O D unit...Honest.
     The dash cluster is easy to remove...start with the headlamp switch...remove necessary parts to gain access to phillips screws...you can keep harness connected...so you can swap bulb at green OD space...you should have a light to tell if you are in OD...the OD relay lives in dashboard to the left of the glove dept....take out the phillips screws remove glove box....easy ...OD wiring is right there...you'll see.
   Good luck,

         Bilbo