Personally from experience on my 1992 Oldsmobile 98 Regency 3.8L to be a Relay/Fuse Issue Normally located right under the Hood Passenger side of the firewall behind a cover normally with 1 or 2 screws (for Relays around 4$ a piece.) The Fuses are located under the Instrument cluster on driver side between FWD brake and Park brake. Due to duel issues is why I suggest fuse or Relay Issues. Other wise it may be just your heater core which is not easy to replace. Good Luck!
May, 9, 2012 AT 7:59 PM
[quote]the temp has gone up to 200 or more[/quote]
That would be because it's not supposed to come on at that temp.
It's a 2 speed system. Low comes on at 212 and high comes on at 226