I have a 94 oldsmobile 88, the problem is this. my blower only works on the 2 lowest settings. it has 4 speeds, and the med/high do not work, i replaced the blower motor and the switch on the dash. any thoughts? its still not working HELP! It was working, first the MED setting went out, now its the HIGH setting
Try changing the blower motor resistor. It controls your fan speeds. Normally, everything will go on that but the fastest speed, but your case may just be an unusual case.
There are a set of resistors, usually in the incoming air flow. There is one for each speed except high. The resistors tend to burn out one by one. I would likely replace them all. In some cars you almost have to replace them all. Resistors are cheap.
There may be two problems in the blower circuit. One is with blower resistor pack, and the other is with the high speed blower relay. On all the speeds except high, the voltage passes thru the high speed relay, thru the resistor pack, to the blower motor. This gives all the low speeds. On high speed, the high speed relay switches from sending voltage thru the resistor pack to applying full voltage to the blower motor.
Shake the wires at the connector to the resistor pack. Also, pull the connector off and spray it with contact cleaner. I’ve had to do this on my 1978 Oldsmobile for the same problem. If this doesn’t work, then you may need to replace the resistor pack.
Is it possible that its the relay, if so which one is it? there are several that are connected to the firewall area, ill check those, and then try the resistor which is only $19.99. i will def keep you guys updated. Ive replaced everything except those 2 things