2006 Chevy Silverado 4wd HD. Blower motor started running all the time even whe the key was removed. I removed the fuse under the hood and the fan stopped. It now works only on speeds 1-4. Is there a high speed relay replacement or do I replace the whole relay system?

The entire control switch seems to work fine. When I replace the fuse under the hood, the blower motor goes back to running continuously on 5 until I pull the fuse back out. Then it goes back to working only with speeds 1-4. The entire control switch seems to work fine. When I replace the fuse under the hood, the blower motor goes back to running continuously on 5 until I pull the fuse back out. Then it goes back to working only with speeds 1-4.

It's definately not the control switch. I just pulled out the blower motor relay, resistor, wiring harness assembly from under the dash on the passenger side and that is the problem. I can see the connections in it are getting fried but nothing has melted yet. It's definately not the control switch. I just pulled out the blower motor relay, resistor, wiring harness assembly from under the dash on the passenger side and that is the problem. I can see the connections in it are getting fried but nothing has melted yet.