I have my heater box bolted up. I've got 3 wires coming from it, a blue, orange, and yellow. On my car I have a whole load of wires to choose from including a relay and 2 or 3 connectors. What can I eliminate and what 3 wires do I need for my heater box? And do I still need this relay?

 

Take a look at this thread in the Cooling board. It has the wiring diagram for the blower motor. You can also visit this link and scroll down the page to Fig. 57 and take that link. Note that the blower motor wiring is the same as the diagram in the referenced thread.

https://www.thirdgen.org/forums/cool...s-blk-ppl.html

http://www.autozone.com/az/cds/en_us...rInfoPages.htm

Yes you need the realy. The blower motor current draw in the "HIGH" speed switch position exceed the current rating of the switch contacts. So the realy bypasses the switch for powering the motor in that speed. Note also that for HIGH speed the blower motor is connected directly to the battery, via a fusable link.

Good Luck getting everything connected....

Dave

 

Okay, so I'm assuming by "high" your talking about the highest of the three settings available with the heater only box? Because the AC blower had 4 speeds plus a MAX, so basically 5.

So I'm going to be taking the wire that has power with my fan level switch at 3:00 (highest setting) and sending it to the relay, which will be giving power to the blower motor.

 

Well, if I understand you correctly, you have a car with AC in it. You removed the AC and installed a heater only box in the engine compartment. You left the AC/Heater controls in the dash the same.

As such, you are mixing two different systems into one system. So I am not clear on where the Orange, Blue and Yellow wires from the heater box are actually connected at the box. Do all three go to the resistor, with the Orange also going to the blower motor? ( The AC sytem has four connections to the resistor, Yellow ...low speed, Tan ....M1 speed, Blue....M2 speed, Purple all speeds from resistor to the blower motor.)

Can you post a connecgtion diagram for the wires on the heater box yo installed? Then I will see if I can figure out how to connect it to the wiring to the AC/ heater controls.

Dave