My 1990 Bonneville blower fan only works in the high position, and it doesn't take long for me to get too hot with the heater going full blast. Do I have a bad relay somewhere? I would appreciate help of any kind.

HeyU

HeyU, My FSM says to run what they call a "Blower Feedback Test".
Measure Resistance at Heater and A/C Control Assembly Connector (Disconnected)
Ignition Switch must be OFF.
Connect a fused jumper across Blower Motor connector terminals A & B
Measure Between L(PPL) & Ground
Correct Resistance should be less than 3 ohms.
Check Relay Center Fuse 1, PPL (65) wire and ORN (761) fir an open or short to ground.
If Resistance is correct, check GRY/BLK (754) wires for short to Battery. If wire is OK, replace Heater and A/C Control Assembly.

BUT, This info is from my 91 Olds FSM. Although our cars are kiss'n cuz'ns. Things are not necessarily the same. I'm sure the Electrical Guru'* will give you additional info on your problem. Good Luck.

Oh, and Welcome to the Bonneville Club.

Is the car an SSE with the electronic climate or does it have the *****?