Bypass ignition switch for blower motor

[Teejaym2500]

I've had "the problems" with my 2003 2500 SLT heating / ac system. Right now, I'm replacing the burned ignition switch. The splice pack I got with the female plug [Mopar Part # 05183441AA] doesn't have the gauge required for the blower motor power. My plan is to by-pass the ignition switch for blower motor power an use 10 ga. running through a toggle switch. Does anyone know if this will work?

 

[Ozymandias]

Don't use a switch, install a heavy relay and use the ignition switch wires to switch the relay.
That's my plan for the future.

 

[Teejaym2500]

Don't use a switch, install a heavy relay and use the ignition switch wires to switch the relay.
That's my plan for the future.

Thanks, Ozymandias. I'm not sure how that wiring would be accomplished, but will work on it. If the power in and power out for the blower motor doesn't go through the ignition, it will need an on off switch before the relay, no,?

 

[Ozymandias]

Nope, you splice the relay into the existing harness, sadly i can't draw a plan here for you, its really easy.
The only wire you need to add is the ground for the relay.

 

[cerberusiam]

Check the wiring diagram first to make sure it is actually powered thru the switch. Most of the accessories are powered out of the FCM anymore so you do not need a heavy wire in the switch to carry a load, it is just a relay in the FCM it activates.

 

[Teejaym2500]

Thanks to Ozymandias and Cerberusiam. The blower motor power goes through the ignition switch. You can see the correct wire immediately as it's blackened, crispy and melted. My take on this is to connect power from the battery through a relay to the blower motor and remove the existing "to the blower motor" wire from the switch. I'm thinking of using 2/0 stranded for this....

 

[BigPapa]

Here ya go.

 

[Teejaym2500]

Thanks Big Papa. My service manuals are in NJ but I'm in FL helping out my 93 yr. old M-in-law. I do have my Haynes, but it's wiring diagram is pretty basic. The ones you have provided are very useful. Thanks again.

 

[Teejaym2500]

Know I know relays and how to wire them. This video is very helpful for that:
Video link

I couldn't have gotten this far without the help of Ozymandias, Cerberusiam and Big Papa. Thanks, guys!