lets see if i can explain this right.

i just installed my non ac heater box. the car originally had ac so the heater controls have the 4 speed. i bought a new relay but got confused they gave me the half rounded one and the box has the square hole so i had to modify the hole.

anyway the motor does not work on the last speed is it supposed to work or am i confused and it's not gonna work?

thanks

 

Let me see if I can get this right. Start troubleshooting from the switch to the motor and see what you find. In particular, there is a fusible link that delivers power from the batt (terminal is actually on the starter, which acts as a distribution block) to the high-speed relay, which I assume was the one you were referring to. Also see that the relay is the exact same one that was originally used for the system. Failing that, check the motor to see if it has not been burned up in any way.

 

if u used the stock heater motor, stock resistor block, then it will only have 3 speeds.

the four speed when u had the a/c box was because that motor had a separate connection for the full 12volts through the relay connection.

when i installed my heater bob i just have the 3 speeds and it give me plenty of heat power.

the relay i just disconnected and stuff te harness depper in the corner of the firewall.