Sometimes works other times turn on switch and wait 10 to 45 seconds before lights. Is it the ballast or should I try replacing bulb, switch and ballast in that order until problem fixed.
thanks

Check the lamp for black rings near the socket ends. If it has black rings the gases are cabonizing and lamp is essentially burning out. I would check for this first. Next thing I would check is the sockets, be carefull here, make sure elctricity is off because the ballast boosts the voltage. Look to make sure the socket hasn't been broken due to improper lamp changing. I'm not sure what kind of florescent fixture you have and where it is, if it's in a non heated area it could be you need a high output fixture which has a ballast suitable for cold areas and would eliminate the delayed start. Also, at times depending on the fixture, it can be cost effective to just replace the whole fixture rather than replacing a ballast.

[This message has been edited by Wirenuttt (edited 11-27-2002).]

Does the fluorescent fitting have a plug-in
Starter,as it sounds like this, may be faulty.

Try this link from the Advance Transformer Company. There are arrows at the bottem of each page to advance to the next topic.
http://www.advancetransformer.com/techcenter/flb/purpose.asp

Trumpy, that's one thing I forgot about was the starter, haven't replaced them in a while since the ballasts have advanced. Bet your right on that one.

It is a kitchen light with 2 40watt U bulbs with ballast

Check if the bulbs are seated in the sockets.
Check if the bulbs are "good" visual, or replace with two known "good" bulbs.
If the "good" bulbs don't light, or take time to light, and the sockets are good, then all that's left is the ballast.
From your first post, an educated guess is "bulbs".
John

Check to make sure the fixture is properly grounded. Fluorescent lamps use the grounded reflector as a starting aid. If you already tried replacing the lamps try a different brand of lamps.