my a/c only runs on high
if your fan is not going on it can be the relay, or a broken temp sensor. the AC only running on HIGH that can be a problem with the switch unit. all is very easy to replace. any moron from AUTOZONE can tell you how to do it.
Sounds to me that if 1-4 dont work, but your blower motor only works on five than its your blower motor resistor. When replacing the resistor which is typically in the HVAC case on the passenger side, inspect the connector for damage because when the resistor goes it likes to take out the connector also.
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