the heater of my buick reatta 89 some times it works and some times it dosen't whats the problem and right now is 3 day and i don't work.
Prob. the vacuum valve that opens to allow hot water to run thru heater core..??
Thanks for the help,now were is this vacuum valve,on the car i can find it?
Should be on the heater hose under the hood near the firewall passenger side..Good luck.