blower trouble

[Tom Williams]

My 04 Trac has a blower problem. It wont blow on 4, only 1-3. I changed the resistor block, below the blower, also cleaned the connector. Still no high speed. Any ideas? Thanks Tom

 

[Chris Taylor]

Can you take a test probe and see if any juice is getting out of the switch when the switch is on 4? If no juice, then possibly the switch is bad. On settings 1-3, the juice goes through the resisitor block with each higher setting having less resistance. I don't have the electrical diagrams for the ST, but on my older F150, the 4 setting goes straight to the motor and bypasses the resister block.

 

[Evan F]

a/c control head

 

[Kevin Palmer]

It also goes thru the block on high speed but it is not resisted. Simply a straight shot thru the block.



Do the switch test before you go any further as it is the next cheapest option...