Replaced A/C Fan Motor and Module. Now Fan Constantly Runs

[Imatk]

About three months ago my A/C fan module went out so I was only able to select the "high" speed of the fan. The other speeds didn't work.

So I replaced the module, and all was fine... until it burnt out again about three weeks ago.

Doing some research, found that it's likely the original fan having too much resistance when it's in use which would cause my module to burn out that quickly.

So I replaced the entire motor with a Motorcraft fan. I also replaced the module again with a Motorcraft part.

BUT the new fan had a different connector that I had to solder in.

I made sure the mark which wire went where on the old connector, so that when I connected the new one it would be on the same leads.

The fan works just fine at all speeds, BUT it never turns off when I move the selector to the "O" symbol. It just always runs now.

It does turn off when the engine/key is off, but as soon as I startup the fan starts blowing on the lowest speed even when in the off position.

Any ideas what's going on with this?

 

[BlckBox04]

sounds like it's running on a constant circuit and it's supposed to have a relay to kick it on and off

 

[Vinnie_B]

The Air Conditioning (A/C) Is Always On:


*Possible Causes:

A short to voltage in circuit
A short to ground in circuit
PCM
Smart junction box (SJB)
EMTC module (Electronic Manual Temperature Control)
A/C cycling switch
A/C control relay
A/C clutch air gap

This is going to require extensive electrical testing to rule out cause of problem. I would also check the blower motor relay for proper working condition first. I believe F2 fuse 30amp is for the blower motor, pull it first before pulling out the relay. There is also a (possiblity) of a defective module. It would need to be ruled out. Good Luck @Imatk




Lightning FastElectrical Automotive Repair LLC
PM Me or [email protected]
Remote or Local (On Site) Technical Repair

 

[hotcobra03]

Never seen inside of this car,,

But have 2010 tundra
The blower always runs.
Has a air recirculating button,

If I hit that switch, blower shuts off, dumb.

 

[Vinnie_B]

Never seen inside of this car,,

But have 2010 tundra
The blower always runs.
Has a air recirculating button,

If I hit that switch, blower shuts off, dumb.

This is the first Ive ever heard of in a mustang.

 

[Vinnie_B]

Im thinking if this just occured after the install of the module and motor thats what he needs to rule out first. Either a defective module or wiring issue?????

 

[Imatk]

Yeah I thought maybe because the wiring had to be redone for the new motor that the wires were somehow "crossed" (there are only two) but I made sure that the same wires that I removed matched the new plug.

That's the reason it had to be rewired, the plug was different.

But I don't know for sure.

 

[Vinnie_B]

Did this just start to happen after you did the install?

 

[Imatk]

The Air Conditioning (A/C) Is Always On:


*Possible Causes:

A short to voltage in circuit
A short to ground in circuit
PCM
Smart junction box (SJB)
EMTC module (Electronic Manual Temperature Control)
A/C cycling switch
A/C control relay
A/C clutch air gap

This is going to require extensive electrical testing to rule out cause of problem. I would also check the blower motor relay for proper working condition first. I believe F2 fuse 30amp is for the blower motor, pull it first before pulling out the relay. There is also a (possiblity) of a defective module. It would need to be ruled out. Good Luck @Imatk




Lightning FastElectrical Automotive Repair LLC
PM Me or [email protected]
Remote or Local (On Site) Technical Repair

The A/C is not always on. It's only the fan is always on. And that only happens when the car is on (key is turned into the accessory or the engine is started.)

 

[Imatk]

Did this just start to happen after you did the install?

Yeah. Before when the selector was set to this position, the fan was off.

 

[Vinnie_B]

Yeah. Before when the selector was set to this position, the fan was off.

Yea that s off Position

 

[Vinnie_B]

Did you check the blower motor fan relay? Thats were i would start.

 

[Imatk]

No I haven't

 

[Vinnie_B]

I'd check the relay and make sure its working correctly first! Than I'd check those two wires and make sure there not crossed up for the motor plug. Need a electrical print so you know what those two wires are for and how there used in the circuit.

 

[Vinnie_B]

After you check the relay. If its good, check this as well.......Power comes from the selector switch dial to the blower motor. Pull the plug off the motor and check for voltage at the plug. With the selector switch in the O/OFF position there should be no power at the plug. If there is your selector switch is bad.

 

[hotcobra03]

Wanted to post some information from manual,,

Testing/diagnostic
And wiring,

See 2 opinions.

Auto wiring

Repair content for 2013 Ford Mustang(2).PDF

Shared with Dropbox

www.dropbox.com

Testing/diagnostic

Repair content for 2013 Ford Mustang.PDF

Shared with Dropbox

www.dropbox.com

If you need something more or other

 

[hotcobra03]

Repair content for 2013 Ford Mustang(1).PDF

Shared with Dropbox

www.dropbox.com

More wiring

 

[Vinnie_B]

Wanted to post some information from manual,,

Testing/diagnostic
And wiring,

See 2 opinions.

Auto wiring

Screenshot 2022-04-074585747727712135591.png

Shared with Dropbox

www.dropbox.com

Testing/diagnostic

Repair content for 2013 Ford Mustang.PDF

Shared with Dropbox

www.dropbox.com

If you need something more or other

Im not sure if he has a 2013 @hotcobra. His personal profile says 06 Mustang GT

 

[Imatk]

Sorry it's a 2007 GT500

 

[Vinnie_B]

Sorry it's a 2007 GT500

Keep us posted on your diagnosis so we can help you get this resolved!