Heater doesn't work

[Petmils 1957 4DR Belair]

My heater on my 57 chev doesn't work it did work but not now. I notice there is a blue wire to power, orange to low speed, green to medium, and yellow to high, those all go a relay then to the motor... I have a tester any ideas where to start the fuse is ok... Thanks Peter

[acardon]

I notice there is a blue wire to power, orange to low speed, green to medium, and yellow to high, those all go a relay then to the motor... I have a tester any ideas where to start the fuse is ok... Thanks Peter

The wires from the switch go to resistors to control the speed and not a relay. http://www.trifive.com/garage/57%20Chevy%20Assembly%20Manual/101-2.gif
The first thing I would do is disconnect the connector on the brown wire under the hood and jumper 12 volts from the battery to the motor to see if it runs. This should make it run on high speed. Here is the connector from the blower motor....http://www.trifive.com/garage/57%20Chevy%20Assembly%20Manual/101-4.gif
If the motor runs, then check all the wires to the resistor box for voltage. If none of the wires have power in the different positions, the switch is probably bad. According to this diagram, I think you have the hi and low speed wire colors wrong. ....http://www.trifive.com/garage/57%20Chevy%20Assembly%20Manual/12-28-01.gif

[Petmils 1957 4DR Belair]

Don this great I Know this will work . i just need to put my mind to it.. Where do you get all the wiring Diagrams from... Peter

[acardon]

Where do you get all the wiring Diagrams from... Peter

Those are in the assembly manual and are in the library section of this site.

[Petmils 1957 4DR Belair]

Don see my other post on the ig switch i think my heater doesn't work because the pink acsss wire is not hooked up..

[Petmils 1957 4DR Belair]

Heater now works thanks all Peter