Where does green wire from blower motor lead to on 1970 Dodge Charger with A/C??

[Blakcharger440]

I am trying to figure out where the green wire for the blower motor leads to for a 1970 Dodge Charger with air conditioning? Does anybody know and can help me out?

[John_Kunkel]

The dark green wire goes from the blower motor resistor to the motor.

[Blakcharger440]

The dark green wire goes from the blower motor resistor to the motor.

On the blower motor resistor there is a black connector there with brown,light green and 2 dark green wires...but just below that connector there is a single spade with nothing on it...I ran the blower motor to that spade and turned ignition to the ON position and the blower motor started running...and I hadnt even touched the FAN slider button yet  so that is not the correct power for the blower motor.

Anybody have any input?

[Nacho-RT74]

68-69, but I guess 70 is pretty much the same because 71/74 are also the same at least on this ( with diff control unit of course )

the dark green wire can be spliced straight to the output resistor plug prong or the AC control plug for the lever function,... will be the same but better to the resistor block.

[Blakcharger440]

68-69, but I guess 70 is pretty much the same because 71/74 are also the same at least on this ( with diff control unit of course )

the dark green wire can be spliced straight to the output resistor plug prong or the AC control plug for the lever function,... will be the same but better to the resistor block.

Hey Nacho,

Is that AC & Heater blower switch located on the dash slider control panel? I plan on splicing into that green wire that leads to that switch since I cannot find where the original heater blower wire is at in the wiring loom.

Thanks for posting that diagram as it helps alot!!!

[Nacho-RT74]

I was to post it should be on Wiper motor plug since there is where all accesories uses to run... went to confirm and my thought was correct.

B cavity of the bulkhead plug... at least on 69 diagram

and couldn't be on another way... the compressor wire just at a side

[Blakcharger440]

Now I am confused.

The 1st diagram shows the green wire of the AC /heater blower motor leading to the blower motor resistor.

The 2nd diagram shows the green wire of the AC/heater blower motor leading to the wiper motor B terminal on bulkhead.


Which is correct? 

I was just going to connect the wire that comes off my blower motor to the other green wire that comes off the blower motor resistor. Would that work?

[Nacho-RT74]

The AC diagram is illustrative just expreselly showing the cab AC harness section, not saying will run straight. Of course should run through the bulkhead. The only wire I know runing straight through the firewall not throught the bulkhead on 2nd gens could be the tach one if equipped, and cruisse control harness.

Check the bulkhead wiring on back side to see if you find the green wire getting into. Don't you have the blue compressor wire getting into the wiper plug too?

If you have the green wire getting to the B cavity on cab side why worry about run it straight? Use the stock provision, specially if car is factory AC. Wire must be there.

[Blakcharger440]

The AC diagram is illustrative just expreselly showing the cab AC harness section, not saying will run straight. Of course should run through the bulkhead. The only wire I know runing straight through the firewall not throught the bulkhead on 2nd gens could be the tach one if equipped, and cruisse control harness.

Check the bulkhead wiring on back side to see if you find the green wire getting into. Don't you have the blue compressor wire getting into the wiper plug too?

If you have the green wire getting to the B cavity on cab side why worry about run it straight? Use the stock provision, specially if car is factory AC. Wire must be there.

Hi Nacho,

The problem is that I had my wiper motor restored on my 1970 Charger RT 440 4speed car so it never came factory with AC although I am putting AC on it. The car does not have any wires leading to the A & B plugs of the wiper motor connector at the bulkhead.

So are you saying that I can just run the green wire from the blower motor to the B slot on the wiper motor connector at the bulk head...and run the blue wire from my AC compressor to the A slot on the wiper motor connector?

I appreciate your help by the way.

[Nacho-RT74]

If the car didn't came with factory AC mostly sure you won't have those wires on back of bulkhead ( cab side ) installed. Not at least the Compressor one. Blower one should be there though because heater should use same path to source the blower for heater... unless is a heater delete option LOL

Check on back of bulkhead at cab side for that.

You mentioned the block resistor got two darl green wires spliced into the plug. That's mostly sure a sign the blower wire is pretty much right there on bulkhead. One of the splices coming from blower lever switch, the other one running to bulkhead.

You can run compressor wire there too at A cavity  and run the wire from there up to compressor function switch inside the cab.

At the end, having or not the wires on bulkhead, you can use those provisions for that like factory did and match the stock configuration.

[Blakcharger440]

If the car didn't came with factory AC mostly sure you won't have those wires on back of bulkhead ( cab side ) installed. Not at least the Compressor one. Blower one should be there though because heater should use same path to source the blower for heater... unless is a heater delete option LOL

Check on back of bulkhead at cab side for that.

You mentioned the block resistor got two darl green wires spliced into the plug. That's mostly sure a sign the blower wire is pretty much right there on bulkhead. One of the splices coming from blower lever switch, the other one running to bulkhead.

You can run compressor wire there too at A cavity  and run the wire from there up to compressor function switch inside the cab.

At the end, having or not the wires on bulkhead, you can use those provisions for that like factory did and match the stock configuration.

Hey Nacho! I ran a green wire from my blower motor to the B slot in that top wiper motor connector and now my blower motor works very good and I am able to select what seems like 3 different speeds on my dash control.....the problem is now that my blower motor starts running immediately when the key is turned to ignition on position.

Is the blower motor supposed to be always running when the ignition is in the on position?

[igozumn]

I think not.  When you choose heat, defrost, a/c, ect, it sends power to the resistor/motor circuit, and then you'd select, low/med/high.  When you push "off" the motor should stop running. 

[Nacho-RT74]

Some problem with the switch on control...

Or some wire inverted in resistor block plug or control switch?

Or incorrect control switch...

[Blakcharger440]

I have the correct AC switch on the dash controls but here is what I have done. I disconnected the tan wire at the heater blower motor resistor and now the fan only starts running when I start pushing the FAN button in to select a speed in which it seems there are two speeds. The other buttons seems to work correctly as well.

[Nacho-RT74]

Yes, the tan wire is a default source no matter the speed you have. You can set mid or high speed and tan wire will be allway hot straight from the control switch. This is because the tan wire drives the higher resistor rate and when you select any other speed by ohms law the load will flow by the smaller resistance existant. However this wire must be off with everything off

Tan wire is sourced from black traced wire comimg from dash harness ( C1-14BK* ) once you set any function of the AC switch control, except heater and deff where it changes to Brown wire to feed the Heater-deff speed, which is slightly slower than the lower AC speed going through the THREE resistors in series, and is just one speed available for it.

For some reason the tan wire coming out from the 6 ways plug is not being cut when AC  switch is in off

Black and tan wires terminals on back of switch should be cut with everything in off. If not, something is happening on switch.

I remember having an issue like that on some switch I tried to fix looong time ago.

[Blakcharger440]

Yes, the tan wire is a default source no matter the speed you have. You can set mid or high speed and tan wire will be allway hot straight from the control switch. This is because the tan wire drives the higher resistor rate and when you select any other speed by ohms law the load will flow by the smaller resistance existant. However this wire must be off with everything off

Tan wire is sourced from black traced wire comimg from dash harness ( C1-14BK* ) once you set any function of the AC switch control, except heater and deff where it changes to Brown wire to feed the Heater-deff speed, which is slightly slower than the lower AC speed going through the THREE resistors in series, and is just one speed available for it.

For some reason the tan wire coming out from the 6 ways plug is not being cut when AC  switch is in off

Black and tan wires terminals on back of switch should be cut with everything in off. If not, something is happening on switch.

I remember having an issue like that on some switch I tried to fix looong time ago.

I feel that all the buttons are working properly without that tan wire hooked up to the blower motor resistor...except that now my blower motor seems to have only 2 speeds....is that correct?

[Nacho-RT74]

Yes because the 3rd speed which is the lower one is feeded throught that tan wire when arriving to the block. This same wire is spliced to feeds the mid ( labeled as "low" on diagram ) and high speeds when one of these is selected. When the mid and high speed are selected no matter if low speed keeps sourced at resistor block since mid and high will be running throught less resistance paths on resistor block and the load will run easily on those than the one coming from tan wire straight to the block

The fact is the tan wire must be feeded JUST when AC, Max AC or VENT are selected. Otherwise something is wrong into the switch

[Blakcharger440]

Yes because the 3rd speed which is the lower one is feeded throught that tan wire when arriving to the block. This same wire is spliced to feeds the mid ( labeled as "low" on diagram ) and high speeds when one of these is selected. When the mid and high speed are selected no matter if low speed keeps sourced at resistor block since mid and high will be running throught less resistance paths on resistor block and the load will run easily on those than the one coming from tan wire straight to the block

The fact is the tan wire must be feeded JUST when AC, Max AC or VENT are selected. Otherwise something is wrong into the switch

I noticed that no matter what buttons I push on my AC/heater control switch that none of my vacuum actuators open any of the doors at all. None at all. Does that mean that I have a bad switch.... I did notice that I can manually open the fresh air door on the AC box using my hand and it will close when I start the car but will not open at all no matter what buttons I push and I can do the same thing with the defroster vent doors.

I have another switch from a different AC/Heater control assembly that I was planning to install just to see if that was the cause of my problems....I noticed my spare switch has a different part number than the one that is currently installed but they look identical in how they are made from what I can see on the outside...just different part numbers. Do you think they could be different on the inside?

[Nacho-RT74]

I have allways wondered about that. Many supersedes numbers around which I have no idea which ones are really the same than others