My '94 non-turbo 850 has over 500K miles. the all the dash warning lights flash on - not all the time, but at least some of the time while I have driven over the past week. Happens in rainy and dry weather. Sometimes it occurs when I hit a bump, other times when I an on smooth road. It still has the original bosch alternator; I changes the brushes abt 8-9 years ago. Has a new battery (less than a year old). and battery connections are tight.

I tested the alternator, and it is charging within spec both at idle, 1500 rpms and 2000 rpms with load. It does bounce around a lot in terms of the reading - does this indicate a problem? should the volgate be steady? The idiot lignt for the alt does not ever come on seperately - only with all the other lights. The belt appears fine.

I am assuming there is a loose wire somewhere - would it typically be a lead to the alt? When I changed to timing belt last september, I spun the alt pulley an there was some drag on it, and given it's age I'm thinking of replacing it - but would like to make sure it not some other spurious issues.

I would appreciate any help in keeping this old volvo running. Its been a daily driver ever since it came of the line.

thanks
mark