The thing is to test it before buying a new one. I believe a scanner can turn the two speeds on but it will cost to have someone hook it up. If your handy, you can get under the car, unhook the electrical connection to the fan and attach hot and ground wires to the wires leading to the fan motor to see if both speeds work. You can also swap the high speed relay with the horn relay in the fuse box under the hood because they are both the same. There's no way to check out the PCM without that scan tool. Anyway, here's how it all works.
