And to throw another twist into the mix, mine used to read at about the M while moving and go up to the A/L when sitting at idle, then go back down once moving again. I replaced the thermostat last summer and before I changed the gauge faces to the BNM ones, it never went any higer than the R at idle and sat at the O most of the time. Of course, sometimes the gauge won't even register or will die and not read at all, so it could be the sending sensor has gone bad causing this to happen...
