Heater box replacement

The wiring harness is different also.

'We ordered the wrong harness for our 71 valiant. It is an A/C car and we got a heater only harness...

However, if you study the wiring diagrams, we were able to use the old A/C wiring with the new harness, by just transferring the main power feed wire from the heater only terminal into the old harness power feed connector....

On the a/c car, the main power feed wire is black and goes to the a/c control, then the a/c control feeds the power into the blower switch...

For the heater only car, the main feed wire is black and goes in the center terminal of the blower switch.

If you find a heater only wiring, then just pop the black main power feed from the old a/c harness out of the connector and then install it to the center terminal for the blower on the heater only wiring and you'll be good....