AC dash Fan Speed issue

[Savmav_coach]

Hello Everyone,

I have a 2015 Ace 30.2 and the highest fan speed on AC dash is not working. Low & mid speed are ok. But the highest isnt. Anyone had this issue before? Remedies?

Thanks

[Jimbo56]

I don’t have that problem but a company named ProAir does the AC unfit for Thor. You might see if you can look up a customer service number online.

[Jimbo56]

https://www.proairllc.com/contact/

[OldWEB]

Originally Posted by Savmav_coach

Hello Everyone,

I have a 2015 Ace 30.2 and the highest fan speed on AC dash is not working. Low & mid speed are ok. But the highest isnt. Anyone had this issue before? Remedies?

Thanks

On Ford there is typically a blower motor resistor pack that limits the current for lower speeds, but if yours is not working on High, then the resistors are 'out of the circuit'. So i would guess it is the speed switch on the dash (or associated wiring), as High will by-pass the resistors.

It is so hard to find schematics online, but most blower motor circuits are similar.
Here is a 1999 Super Duty one:

[Savmav_coach]

Originally Posted by Jimbo56

https://www.proairllc.com/contact/

Thank you for the info.

[Savmav_coach]

Originally Posted by OldWEB

On Ford there is typically a blower motor resistor pack that limits the current for lower speeds, but if yours is not working on High, then the resistors are 'out of the circuit'. So i would guess it is the speed switch on the dash (or associated wiring), as High will by-pass the resistors.

It is so hard to find schematics online, but most blower motor circuits are similar.
Here is a 1999 Super Duty one:

Thank you for the info, this diagram is very useful. I will double check the wiring and connections. I thought of the resistors too, but like you said, the high speed should still be working if the resistor is the issue. I'll try my luck fixing it this evening and will provide update for everyone's future reference.

[OldWEB]

So I am looking over the diagram again and I see in this instance if the High contact was "open" (non-functioning) then the blower motor should still run on Lo as that is exactly what the Low position is... Open circuited (all resistors and fuse in the circuit)
So on High, is the blower in fact running as Low or nothing at all?

[Savmav_coach]

Originally Posted by OldWEB

So I am looking over the diagram again and I see in this instance if the High contact was "open" (non-functioning) then the blower motor should still run on Lo as that is exactly what the Low position is... Open circuited (all resistors and fuse in the circuit)
So on High, is the blower in fact running as Low or nothing at all?

You're right -- on high, the blower is running low air.

[OldWEB]

Originally Posted by Savmav_coach

You're right -- on high, the blower is running low air.

So, I would then suspect the contact #1 in the blower motor switch or the wiring (possibly orange wire/black strip) to it from point S152 in the diagram or a overheated connection. The rest of the circuits then appear to be working... pull out the multimeter.

[BASSMAN]

I bought the digital service manual for my 2017 Thor Axis, it has all the wiring diagrams and they were not what I was expecting but wile going through all the pages of the manual I did see something that caught my eye and not sure if its just for the state of California but it said that Ford had to warranty the engine for anything smog related for 15 years or 150K miles, that would be any thing in the fuel or exhaust system and anything electrical that controlled the engine

[16ACE27]

Originally Posted by BASSMAN

I bought the digital service manual for my 2017 Thor Axis, it has all the wiring diagrams and they were not what I was expecting but wile going through all the pages of the manual I did see something that caught my eye and not sure if its just for the state of California but it said that Ford had to warranty the engine for anything smog related for 15 years or 150K miles, that would be any thing in the fuel or exhaust system and anything electrical that controlled the engine

Where did you buy this "manual"?

[BASSMAN]

I did a google search and its the Ford manual, not sold by Ford but a private business, I recall it was around $150.00 an it was like 1200 pages or more, I still have it in one of my down load files and if I can see who I bought it from I will post it, my fan motor for the dash heater quit an I tested everything and was not getting power to the dash controls, turns out under the drivers side dash panel was a multi pin plug that had disconnected itself,

[Galobo]

Try to locate/identify the blower control module, it controls your fan speeds.

[larrysfixit]

On my 2018 ACE the connector to check for power is right in front of the pax seating you can see it from the floor. In the blower housing. You could check the voltage at the plug with a volt or multimeter If you have power there from the 3 input wires (12 volts) to the black depending on the switch setting, then the switch should be OK. If not check the switch or a bad wire connection. If you have the power then check the resistors by removing the 2 screws. Pretty easy job this time