07navi
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Put a little tin foil in there and tape it.
AC issue...
- Thread starter legendary70
- Start date
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I thought you were getting better and then.....
BAM back to the hack.
@MrSticker was right you seriously need to put a disclaimer notice in your signature.
07navi
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Novices never get innovative because they can't think out of the box.
Clemson82
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I also had to replace the blower motor switch. I bought this part on Amazon, and replaced it using a video on you tube and info on this website. Took 20 mins, and I have almost zero mechanical ability. You may have to also replace the wiring harness, but I haven't had to...yet.
https://smile.amazon.com/gp/product/B0080DWR5A/ref=ox_sc_saved_title_1?smid=A3KQI776IVRETC&psc=1
https://smile.amazon.com/gp/product/B0080DWR5A/ref=ox_sc_saved_title_1?smid=A3KQI776IVRETC&psc=1
07navi
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Lotta' money for a little switch.
99WhiteC5Coupe
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mjp2
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Mine's been getting worse as well. I have one of these sitting in the garage and will likely solder it in this weekend.
https://www.amazon.com/gp/product/B000IYM05G/
It's fine when my wife's in the truck and I can just have her kick her leg to get things working but it's a hassle when I'm driving by myself. Don't want the blower going out in the winter when I need the defroster to work.
Any luck figuring it out so far?
I would start by checking the blower motor relay switch wiring harness. It is under the glove box. Check out that amazon link that Clemson82 posted.
The exact same thing happened to my wife's 2017 Expedition EL Limited. While driving one day, she noticed the AC blower cutting in and out. Not knowing anything in particular about this issue with the Expys (and it is a legitimate, common issue), I grabbed the wiring harness going to that blower motor relay switch and moved it around. The blower started working again.
When you move the wires around, the blower motor will turn on and off. After a bunch of research, it appears to be an issue with that relay and/or the harness, and possibly the blower motor. The story appears to be that the system is engineered imperfectly. With my Expy, after disconnecting the harness from the relay, it was clearly visible that the harness had melted a little and was now no longer making an adequate connection with the contacts on the relay. I bought a relay and the harness off of Rock Auto. I think I originally bought a harness from Amazon, but the one sent was not compatible with this class of Expy even though the description said it was. The wires were MUCH thinner than the OEM ones, which is not a good thing. This relay apparently takes a significant current draw (amperage), and an inadequate wire gauge would overheat just the same, if not worse than the factory harness issue IMO. Never go down on wire gauge when doing anything electrical, IMO. That is a bad recipe. So, I'm pretty sure that I ordered the harness from Rock Auto also.
I'm not sure exactly why the OEM harness overheats, but I suspect it is from corrosion due to residual condensation making its way off the blower motor area and finding its way into that harness. All of the contacts had standard white aluminum corrosion, and two of the contacts were partially melted, causing the connection issue. I think that one contact probably was compromised and then did damage to the neighboring one. Ultimately, the relay can go bad too, and overheating is the symptom. However, it may be just the wiring harness that is compromised, which would also create heat. The relay/harness was physically hot to the touch, so I decided to replace the relay too.
Now, for experimentation, I first replaced the harness only, as the relay looked perfect. The AC worked without issue for a couple weeks and it did not get hot at all. I did replace the relay anyway out of prudence, and kept the old one as a backup as I believe that it is still OK. My research also suggested that when the blower motor goes bad, it draws too much amperage which can cook the relay. So, a sporadically working or non-working blower motor (the part that blows air out of the vents) can be bad or going bad, as can the relay and harness. Since they are all part of the AC system, a little trial and error can lead you to a solution.
With that said, my blower motor may still be on its way out. Everything works as it should now, and the connector and relay are not hot, but it makes sense that the blower motor may be on its way out. Living in South Florida, where we use the AC nearly all year, it makes sense that it would wear out quicker than if the vehicle was in a cooler climate.
Hope all of this helps and good luck! Post some pics of your harness and relay connections and what you find. People here will help you out.
I would start by checking the blower motor relay switch wiring harness. It is under the glove box. Check out that amazon link that Clemson82 posted.
The exact same thing happened to my wife's 2017 Expedition EL Limited. While driving one day, she noticed the AC blower cutting in and out. Not knowing anything in particular about this issue with the Expys (and it is a legitimate, common issue), I grabbed the wiring harness going to that blower motor relay switch and moved it around. The blower started working again.
When you move the wires around, the blower motor will turn on and off. After a bunch of research, it appears to be an issue with that relay and/or the harness, and possibly the blower motor. The story appears to be that the system is engineered imperfectly. With my Expy, after disconnecting the harness from the relay, it was clearly visible that the harness had melted a little and was now no longer making an adequate connection with the contacts on the relay. I bought a relay and the harness off of Rock Auto. I think I originally bought a harness from Amazon, but the one sent was not compatible with this class of Expy even though the description said it was. The wires were MUCH thinner than the OEM ones, which is not a good thing. This relay apparently takes a significant current draw (amperage), and an inadequate wire gauge would overheat just the same, if not worse than the factory harness issue IMO. Never go down on wire gauge when doing anything electrical, IMO. That is a bad recipe. So, I'm pretty sure that I ordered the harness from Rock Auto also.
I'm not sure exactly why the OEM harness overheats, but I suspect it is from corrosion due to residual condensation making its way off the blower motor area and finding its way into that harness. All of the contacts had standard white aluminum corrosion, and two of the contacts were partially melted, causing the connection issue. I think that one contact probably was compromised and then did damage to the neighboring one. Ultimately, the relay can go bad too, and overheating is the symptom. However, it may be just the wiring harness that is compromised, which would also create heat. The relay/harness was physically hot to the touch, so I decided to replace the relay too.
Now, for experimentation, I first replaced the harness only, as the relay looked perfect. The AC worked without issue for a couple weeks and it did not get hot at all. I did replace the relay anyway out of prudence, and kept the old one as a backup as I believe that it is still OK. My research also suggested that when the blower motor goes bad, it draws too much amperage which can cook the relay. So, a sporadically working or non-working blower motor (the part that blows air out of the vents) can be bad or going bad, as can the relay and harness. Since they are all part of the AC system, a little trial and error can lead you to a solution.
With that said, my blower motor may still be on its way out. Everything works as it should now, and the connector and relay are not hot, but it makes sense that the blower motor may be on its way out. Living in South Florida, where we use the AC nearly all year, it makes sense that it would wear out quicker than if the vehicle was in a cooler climate.
Hope all of this helps and good luck! Post some pics of your harness and relay connections and what you find. People here will help you out.
