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madstudios
12-16-2016, 03:41 PM
Hi everyone!
I'm having some problems with my AC.
When I turn on the AC, it blows cold and fan is working well. But after 10 minutes of usage, no matter the speed of the fan, i can smell something, like burn plastic, and a smoke start to come out of the vents!
When I turn of the ac and motor blower, the smell and smoke stops.
Could be a bad motor blower?
I was confused about the wiring on the blower motor. There is one plug that is not connected, the only place to plug is on the ground, but it come out from the positive wire, so I've left the way it is.
Thank you!
http://uploads.tapatalk-cdn.com/20161216/2be5c51ac04394b866e5ca7b43dc06b0.jpg


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Mark D
12-16-2016, 03:55 PM
If I'm reading the schematic correctly that disconnected wire in the photo should be connected to the blower motor ground terminal that has the open blade at the top of your photo. I'm not sure if it has anything to do with the cause of the smoke, but it looks like it's a power wire that runs parallel to the motor through an inline diode and then to ground. One of the electrical guru's on the board should be able to give you a better idea of what function the wire actually serves. I think it has something to do with preventing power draw through the fan when it's turned off, so I don't really think it should have anything to do with your smoke issue.

http://dmctalk.org/attachment.php?attachmentid=47899&d=1481921645

madstudios
12-16-2016, 04:40 PM
If I'm reading the schematic correctly that disconnected wire in the photo should be connected to the blower motor ground terminal that has the open blade at the top of your photo. I'm not sure if it has anything to do with the cause of the smoke, but it looks like it's a power wire that runs parallel to the motor through an inline diode and then to ground. One of the electrical guru's on the board should be able to give you a better idea of what function the wire actually serves. I think it has something to do with preventing power draw through the fan when it's turned off, so I don't really think it should have anything to do with your smoke issue.

http://dmctalk.org/attachment.php?attachmentid=47899&d=1481921645

Thanks Mark!
I was wondering what could cause the smoke, besides the blower motor itself... there isn't much eletrical stuff going on in there I suppose.


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David T
12-16-2016, 04:53 PM
That wire goes to the black thingy which is a .5 mf capacitor and then to the ground terminal. Meant to filter out electrical noise for the radio from the motor's brushes. Has nothing to do with the smoke or smell. From your description it sounds like the motor is dying. I would pull the motor out and examine it. One possibility is the plastic squirrel cage fan is rubbing on something and causing the smell. The motor looks pretty clean so I wonder that it is not the motor but something else. There is a resistor block for the different fan speeds. It is that plug next tot he fan motor. Pull it too and see if anything is on it and burning. That resistor can get very hot. When you get the motor out look inside the heater box and clean it out. Maybe some old foam got caught in the wrong place.

Bitsyncmaster
12-16-2016, 05:06 PM
If you had something on the "speed" resistor, that could cause the smoking. You would need to pull that resistor out to look at it.

madstudios
12-16-2016, 05:38 PM
That wire goes to the black thingy which is a .5 mf capacitor and then to the ground terminal. Meant to filter out electrical noise for the radio from the motor's brushes. Has nothing to do with the smoke or smell. From your description it sounds like the motor is dying. I would pull the motor out and examine it. One possibility is the plastic squirrel cage fan is rubbing on something and causing the smell. The motor looks pretty clean so I wonder that it is not the motor but something else. There is a resistor block for the different fan speeds. It is that plug next tot he fan motor. Pull it too and see if anything is on it and burning. That resistor can get very hot. When you get the motor out look inside the heater box and clean it out. Maybe some old foam got caught in the wrong place.

Here is the photo of my resistor... http://uploads.tapatalk-cdn.com/20161216/901174a8c12db9d477d67751824942c0.jpg


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Bitsyncmaster
12-16-2016, 05:56 PM
Here is the photo of my resistor... http://uploads.tapatalk-cdn.com/20161216/901174a8c12db9d477d67751824942c0.jpg


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Looks clean. So it must be your blower motor smoking.

AugustneverEnds
12-16-2016, 09:35 PM
There might be something trapped in the cage in the blower motor. Mice nests and other nasty things can find their way in there. Worth checking out

Bob635
12-17-2016, 11:40 AM
If you can check the amps the motor is drawn when you first turn it on and then when you start smelling the electrical odor, this might confirm that the windings on the motor are shorting.
Higher amps when it is hot is a symptom of shorted motor wiring.
Bob



Hi everyone!
I'm having some problems with my AC.
When I turn on the AC, it blows cold and fan is working well. But after 10 minutes of usage, no matter the speed of the fan, i can smell something, like burn plastic, and a smoke start to come out of the vents!
When I turn of the ac and motor blower, the smell and smoke stops.
Could be a bad motor blower?
I was confused about the wiring on the blower motor. There is one plug that is not connected, the only place to plug is on the ground, but it come out from the positive wire, so I've left the way it is.
Thank you!
http://uploads.tapatalk-cdn.com/20161216/2be5c51ac04394b866e5ca7b43dc06b0.jpg


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madstudios
12-17-2016, 04:05 PM
After a good cleaning in the blower and resistor, I've run the ac about 40 minutes and Everything looks ok now!
Tomorrow I'll test again...
Thanks!



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madstudios
12-18-2016, 06:13 PM
Hi everyone.
Today, after a long trip, I've discovered that the smell and smoke only occurs when the motor is in position 1. No sign of it when in positions 2, 3 or 4. Weird...


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Bitsyncmaster
12-18-2016, 06:23 PM
Hi everyone.
Today, after a long trip, I've discovered that the smell and smoke only occurs when the motor is in position 1. No sign of it when in positions 2, 3 or 4. Weird...


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Probably something is just burning off the resistor. Do you know if that resistor is new? Other possible cause is the fan speed switch has a bad connection (could be inside the switch) on that speed.

madstudios
12-18-2016, 08:21 PM
Probably something is just burning off the resistor. Do you know if that resistor is new? Other possible cause is the fan speed switch has a bad connection (could be inside the switch) on that speed.

The resistor is not new, but it's clean.
But I'll check the fan speed switch!
Thanks


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Parzval
12-20-2016, 01:42 AM
The resistor is not new, but it's clean.
But I'll check the fan speed switch!
Thanks


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I'd bet my money on that speed resistor. The wires may be clean, but the terminals are rusty. I had this happen on my Chrysler minivan. Smelled burning as well. The corrosion works its way between the wire and the lug it is crimped to. Eventually it starts arcing and then they burn to the point where they no longer make contact. In my van eventually the speeds all died out and it would only work on high (no resistors). It was cheap enough to replace.... though I don't know what a DeLorean one will cost! I won't say your D will catch fire, but I do believe you should replace that resistor. I'm 95% certain it is your burning smell.

Good luck!
Josh

madstudios
12-20-2016, 05:39 AM
I'd bet my money on that speed resistor. The wires may be clean, but the terminals are rusty. I had this happen on my Chrysler minivan. Smelled burning as well. The corrosion works its way between the wire and the lug it is crimped to. Eventually it starts arcing and then they burn to the point where they no longer make contact. In my van eventually the speeds all died out and it would only work on high (no resistors). It was cheap enough to replace.... though I don't know what a DeLorean one will cost! I won't say your D will catch fire, but I do believe you should replace that resistor. I'm 95% certain it is your burning smell.

Good luck!
Josh

It makes perfect sense, Josh!
The resistor costs about 13 bucks, and I'll definitely buy a new one.
Thanks!


Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

David T
12-20-2016, 11:45 AM
It makes perfect sense, Josh!
The resistor costs about 13 bucks, and I'll definitely buy a new one.
Thanks!


Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

You could try cleaning it with some steel wool or sandpaper. After that what is left should burn off quickly.

Edward Davies
06-09-2023, 05:51 AM
You could try cleaning it with some steel wool or sandpaper. After that what is left should burn off quickly.

I do not recommend using steel wool or sandpaper for cleaning, as they can damage surfaces.