2000 Buick Park Ave. Ultra

all at the same time a/c quit working, fan controls work, interior lights do not come on, security light on all time, both check engine& service engine lights came on but went off same day, i have checked all fuses i believe are ok. found 4 fuse boxes what is wrong? Car runs fine.

If the CEL light was on that means an error code came up. That code is stored in the computer. Take it to Advance Auto or Autozone and have them scan the computer codes.

-Matt

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code not just their translation into English and post it back here.