ATC workaround

[thethee]

Honestly, no, I don't think I would swap the box.

That's not just cause I'm in the Netherlands and parts are scarce and costly although it is a factor. Mostly it's because the boxes themselves are identical as far as I can tell, with the exception of the holes for the servo unit and the diode of course. Other than that they're the same, same mode doors, same actuators, same ducts, etc. So there is really no need to swap the housing IMO. All you'd need is the manual control panel and cable to make it work.

BUT since n=1 you'd have to check your own FSM to make sure they are the same.

 

[thethee]

Revisit!

I was having some issues with my blower motor speeds and I had my dash out for upgrading to LEDs inside and out so this seemed like a perfect time to deal with it.

Luckily @wypowerwagon440 kindly provided me with the correct manual blower motor resistor block (p/n 3503779). Was able to successfully rewire my fan speed switch after some wiring diagram detective work. Don't know where, it was probably from Ross or Big John, but somewhere on this forum I learned about reusing factory connectors. Valuable skill to have! Was able to repurpose some of the old ATC connectors that way.

I now finally have full correct manual controls; four speed settings from the fan speed lever and the "off" mode button actually turns off the fan.

Edit: removed the gray wire from the white 10 pin connector and plugged it in the empty socket of the black connector. That gray wire comes from the control panel and provides the low-low fan speed. The dark green in the black connector goes to the blower motor.

 

[commando1]

Revisit!

I was having some issues with my blower motor speeds and I had my dash out for upgrading to LEDs inside and out so this seemed like a perfect time to deal with it.

Luckily @wypowerwagon440 kindly provided me with the correct manual blower motor resistor block (p/n 3503779). Was able to successfully rewire my fan speed switch after some wiring diagram detective work. Don't know where, it was probably from Ross or Big John, but somewhere on this forum I learned about reusing factory connectors. Valuable skill to have! Was able to repurpose some of the old ATC connectors that way.

I now finally have full correct manual controls; four speed settings from the fan speed lever and the "off" mode button actually turns off the fan.

View attachment 586535

Edit: removed the gray wire from the white 10 pin connector and plugged it in the empty socket of the black connector. That gray wire comes from the control panel and provides the low-low fan speed. The dark green in the black connector goes to the blower motor.

Amazing. You have earned my highest respect for jumping over the edge into the ATC abyss.
Seriously.

 

[thethee]

Amazing. You have earned my highest respect for jumping over the edge into the ATC abyss.
Seriously.

Wow, that means a lot, thanks!

 

[thethee]

@75LandYacht as I can't post pics in PMs, can you confirm if these diagrams match the ones in your 77 FSM?

 

[75LandYacht]

@75LandYacht as I can't post pics in PMs, can you confirm if these diagrams match the ones in your 77 FSM?

View attachment 587011View attachment 587012View attachment 587013

The T, ill Pull the manual and have an answer for you this week.