Sorry, I do not have an answer to your question, but I'm having the same issue with my 1999 Oldsmobile Intrigue. Theheat is working on the passenger side, but blowing cold air on the drivers side. Go figure, I'm usually the only person in the car. Have you found out anything yet?
I dunno if this will help, but i had the exact same problem. i found out a "30a fuse" was missing for the air pump under my fuse box near the battery. i bought the fuse at autozone. When i plugged that in and started my heater again, it fixed it right up. I've also read rumors around the internet that if you leave the doors open and disconnect the negative the temp control will reset itself. (didn't work for me though and locked my radio).
You need to add water to the radiator, it may be low and you will overheat your motor.
The heater in a 1998 Oldsmobile Intrigue may be stuck on defrost due to a malfunctioning or stuck blend door actuator, which controls the flow of air between the defrost, heat, and AC settings. Additionally, a vacuum leak in the HVAC system or a faulty climate control module could also cause this issue. It's advisable to check for any vacuum line issues and inspect the actuator for proper operation. If needed, consulting a mechanic can help diagnose and resolve the problem.
I would start by checking the fuse, the relay, and the connector on the blower itself.
Try completely disconnecting the battery for 1 hour then reconnect it. That should reset some door that controls the airflow. I just experienced hot air blowing on the pass side and cold air on the drivers side. I did the reset and now I have heat on both sides. Hope it works for you.
The heater core may be stopped up. Try flushing it, or replace it.
Under the glove compartment. You must remove the decorative panel cover first. And it is in the top right corner under the glove box
A sending unit is an electrical sensor that senses heat and sends a signal to the heat light on the dash when the engine is overheating. It is usually located on the cylinder head, usually close to the thermostat. It is about 3/4" or 1" in diameter and has a wire connected to the tip.
They are threaded, but ypu need a special socket. Also, applying heat helps to loosen it, but they are tough to remove. Just unplug connector.
It's likely there is a leaky air duct at some point behind the dash. Here is the solution. Disconnect the negative terminal on the battery for a least five minutes. Open BOTH drivers and passenger FRONT doors and leave them open. Re-connect the negative battery cable. Shut doors and start the car. Your air should work fine. This ridiculous procedure re-sets the module that controls the A/C & heat distribution. Only GM engineers would come up with this one!!
Most likely a bad heater core
Before looking for the servo check your vaccum line from the back of the engine it goes across the firewall down the passenger side-inside fenderwell, then und&er the battery and back to the lower firewall. Lots of Intrigues battery aicid eat this little black line into around the battery box. This creates no vaccum to the heat & air door controls.
Brimstone - 1998 Heat 1-2 was released on: USA: 30 October 1998