I have a 99 bravada. The heater works barely. It blows just fine and will blow heat but not very hot. Then randomly the AC light will come on and it will start blowing cold. During the summer is the exact opposite it will blow cold the fan will shut off then start back up, blow hot for a second and then the AC continues to work. I have replaced motors, relays, control modules, compressors etc etc.. help.
What makes this problem better or worse?
Heat seems to make it worse (for the AC issue)
How long has your 1999 Oldsmobile Bravada had this problem?
RepairPal Certified shops can diagnose and repair your 1999 Oldsmobile Bravada. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Really need more details about the dash unit - as in - automatic climate control (dual zone) or the 3 button manual climate control..
This is indicative of an intermittent control unit failure / malfunction.
Scan test body control module (bcm) may present clues.
Good luck!
Additionally the engine thermostat may be sticking partially open causing poor heater output - ‘temperature gauge’ will reflect failing (stuck open) t-stat by displaying low temp readings..
Feeling of - holding onto BOTH heater hoses while engine is at normal operating temperature will reveal partially restricted heater core as well - - *BOTH* hoses should be *HOT*..
Ultimately the only sure bet is *hands-on* testing / evaluation - we can only make suggestions.
Additionally the engine thermostat may be sticking partially open causing poor heater output - ‘temperature gauge’ will reflect failing (stuck open) t-stat by displaying low temp readings.. Feeling of - holding onto BOTH heater hoses while engine is at normal operating temperature will reveal partially restricted heater core as well - - *BOTH* hoses should be *HOT*.. Ultimately the only sure bet is *hands-on* testing / evaluation - we can only make suggestions.