Front AC not working

[KassieB89]

2017 XLT 6cyl ecoboost
So, my front ac has stopped working, it no longer blows air out at all hot or cold(the rear is still blowing fine, both hot and cold). I replaced the blower motor, the resistor, and the resistor wiring harness. Whoever had this suv before me did a really horrible job when they "fixed" the same issue(soldered the wires to the pins in the resistor). I made sure to splice in the wiring correctly. I also replaced a couple of fuses that had corrosion on them. After replacing those things, my ac still isn't blowing air in the front. What else could it be? I'm able to turn the ac on/off with the buttons and touch screen and the rear audibly turns off/on. The blend door actuator is acting up(clicking noise anytime I open the door, turn the ignition on, switch from hot to cold), but it's been doing that since we bought the SUV and hasn't caused any issues with the ac(heat was hot, and cold was, well, cold). I'm trying to avoid spending hundreds or thousands on something that could be a simple fix that I can do myself. Any help is appreciated.

 

[max78]

I would start by checking the fuses if you went and spliced things with the battery connected. I think spot 51 is a 40 amp relay for the blower motor.

After that I would check on your clicking blend door actuators. I found out that a faulty blend door will prevent the blower from turning on. I was able to jump relay #3 under the hood and that powered up my blower, but by itself it would never power up. All I would hear is a clicking back and forth under the dash. I found the blend door actuator that was clicking back and forth for as long as it was powered up (because the potentiometer failed internally), replaced it with a new ford part and the blower worked and everything was back to normal.

 

[KassieB89]

I actually unhooked the battery(didn't want to chance getting electrocuted since it was such a hack job done by previous owner). And I did replace the amp relay(its spot 57...I accidentally broke it trying to pull it). I also changed the 10 amp fuse in the box(spot 46) on the passenger side, it was badly corroded. I'll swap out the blend door actuator since it needs to be replaced anyways. Hopefully that fixes it. Thank you.

 

[max78]

In my case unplugging the actuator allowed the blower motor to work until I get a new actuator on hand. Maybe give that a shot?

 

[KassieB89]

I replaced the actuator(made sure everything was lined up correctly). No more clicking noise, but still no air blowing out the front vents. Rear vents are blowing a lot stronger than they were before though...so I don't know if that has something to do with why there is no air blowing out the front. I even went as far as disconnecting the battery, holding the connectors together for a minute and reconnecting(allowing the system to reset before even putting the key in the ignition). I am at a complete loss to what else it could be. We noticed that it was something to do with the wires down by the fuse box on the passenger side when my husband pushed on it with his foot and it would shut off. But since it was still working intermittently and only stopped when pushed on, we didn't bother with it until it went out completely the other day and I noticed that the wire was completely hanging down and then that's when I replaced the parts mentioned in my original post. Have had no other issues with the ac(aside from the actuator). This is really frustrating.

 

[max78]

Have you tried jumping the relay connection to see if it powers on at all? That will help you narrow it down from either a power issue, or a trigger issue.

 

[KassieB89]

Not at the relay under the hood. I don't know how to do that but my husband actually video called me and walked me through how to do it by the passenger seat with the resistor wires during his lunch break at work. He had me check with a continuity probe to see which ones lit up and then had me hold a wire to the ground right there under the fuse box and to each of the wires that lit up on the resistor wiring harness. The blower motor didn't power on at all. I'll try jumping it at the relay next.

 

[KassieB89]

I finally found the problem. It was a faulty resistor!! The brand new resistor I bought was bad right out of the box. I'm updating so that if anyone else comes across this thread in the hopes of figuring out your problem, you'll know what to check. Apparently the resistors are known to be faulty right out of the box. Sometimes you'll get very lucky and the first one is good, or you'll get lucky(like me) and the second one is good. I came across a youtube video and in the comments people were saying that they had bought 3 different resistors that were bad until they got lucky with the 4th one being good. So if you did like me and replaced all the parts, spliced wires properly, checked all the fuses and relays, and checked to make sure there was continuity, and you still don't have air coming out the front vents, SWAP OUT THE RESISTOR until you find one that works! Thank you Max78 for your help, I really appreciate it.

 

[max78]

Wow, that's always a bummer when you are chasing a problem and it turns out to be a brand new part that was supposedly tested good from the factory. . .

Glad you got it figured out!