Q: Heater and air conditioning fan stuck on low

The push button panel for your climate control is also the control unit. It uses the signals from various temp sensors to decide what to tell the climate control what to do. It also decides on the fan speed and sends a signal to the fan speed controller to power up the fan and the electric heater valve to control the temperature. Any or all of these components could be giving you trouble at this point. Rebuilt control units are available for your car but they are not inexpensive. There is no self-diagnostic feature on the ’88 so the only way to check it all out is to get comfortable with a manual and a multi meter. It can be a challenging prospect for the best technicians. If you don’t want to take it on yourself, contact YourMechanic and they can send a technician to your home or office to diagnose the system and tell you what needs to be replaced.