... i went to the 700 faq as directed by the 1800 forum ( seems that older volvo owners seem a little more technically inclined than newer volvo owners)..
after a little screwing around i started the engine, set the blower to auto recirculate switch in, a/c off, and the other knob with the upper lower selections to the 10 o'clock position, ...
with these conditions set, you depress and release (back to off) the a/c button. the blue boarder will indicate fail codes by a series of blinks, i.e. 161 fail code would be 1 blink a short delay, 6 blinks, another delay and 1 blink. the process is repeated till all fail codes are displayed as indicated by a pepeat of the sequence. if fail codes are false or the problem repaired, turning off the engine will clear them.
pretty cool, i got two fail codes ,131 and 161, a dash speaker mounted sensor fail(minor) and a temp sensor no 12 vdc to the sensor near the dome light. will check for volts to the sensor near the dome light next.