Where is the drain for the heating system in your brougham 1990 Cadillac?

In a 1990 Cadillac Brougham, the drain for the heating system is typically located at the base of the firewall, where the heater core is situated. It can sometimes be found near the passenger side, where the heater core hoses connect. If you're experiencing drainage issues or leaks, it may be necessary to inspect the area for any blockages or damage. Always refer to the vehicle's service manual for specific details and diagrams.