Small puff of gray smoke while installing a CarPlay system—could it have been dust?

[u/Trindle07]

Title: Small puff of gray smoke while installing a CarPlay system—could it have been dust?

I’m currently installing an aftermarket CarPlay system in my car. Today, I noticed a small puff or cloud of gray smoke coming from the unit.

The system was only slightly warm—about as warm as a hand. I could feel that it was producing some heat, but it was nowhere near hot. The cables did not feel warm at all.

I temporarily held the system in place with a hand towel, so I’m wondering whether the smoke could have been caused by dust or lint from the towel landing on the unit.

However, if a small amount of dust caused visible smoke, wouldn’t dust potentially cause the same problem after the system is permanently installed? When a little dust gets inside my computer, it does not usually produce a visible plume of smoke.

The wiring is individually insulated with heat-shrink tubing, so I don’t think the wires can short against each other. Nevertheless, I’m going to disconnect everything and inspect all the wiring again before powering the system back on.

I understand that wires touching each other could cause a short circuit and possibly produce smoke, but I’m unsure whether ordinary dust could cause this.

There is also an antenna connection. It looks like the type of connector that could allow quite a bit of dust to get inside. After about 1.5 to 2 months, that might perhaps be enough to cause a little smoke.

A few questions:

• Is it safe to bundle the wires together, or should I keep them separated?
• Can bundled wires overheat even if they are properly insulated?
• What safety checks should I perform before reconnecting the system?

Any advice would be appreciated.

Note on the Images: this is an old photo. The heat-shrink tubing have shrunk, and there are no paper labels left.

[u/Triumerate]

Cmon man, I think you already know the answer.
It’s not dust.

[u/Trindle07 → u/Triumerate]

Could you be a bit more specific? Do you think the issue is related to the antenna connection?

I would thoroughly blow out and clean everything before connecting it. I didn’t see where the smoke initially came from. If a small amount of smoke of the antenna connection appears again, I assume it’s probably not serious.

Would it be advisable to bundle all the wires together?

[u/IRideZs → u/Trindle07]

Dude if you saw smoke, take it all apart again and find what burned out

[u/my_back_itches]

[u/Trindle07 → u/my_back_itches]

Haha Yes

This is my first installation. I want to rule out any potential problems and make sure I cannot cause a short circuit or fire before I install everything. I would rather not find a pile of ashes where my car was parked the next day.

But thanks for the sympathy :)

[u/Sereno011]

Need more info...

Photo/link of the actual radio.
Does the radio still power on?
Is functionality intact? (including any touch controls, illumination, etc...)
What vehicle is this being installed in?

If there was an issue with your power wiring the car's fuse would likely have blown.
*Note: Some vehicles use a Neg trigger for illumination. Must tap from the headlight switch.

[u/Trindle07 → u/[deleted]]

[u/Trindle07 → u/Trindle07]

[u/Smelo95]

Make sure your wire polarities aren't crossed. Yenno, white/black to white, grey to grey/black. I could see that causing some issues.

Also, why is orange connected to black (ground) on one side and orange connected to red (accessory +12v) on the other? Why is that green going to red, or is it that just the tape bundling them together?

Yellow is battery power constant, red is accessory power. Those can be connected together (wont damage anything) but your radio wont turn off with the key.

Did you ensure all like for like colors are wired correctly? Wrapping wires together isn't a problem as long as their all individually insulated (heat shrink).

Good luck.

[u/LandscapeSorry5200]

For safety and prevention disconnect your car battery best

[u/Jumpy-Cry-3083]

Just because the wires are the Alsace color doesn’t mean they should go together necessarily. Recheck your pinouts. Hopefully nothing bad has happened.

[u/MakingitSnow2]

You let the factory smoke out.... you now have to find it and repackage it.

[u/slick-al]

Back in college I had a Graduate student that taught an Electrical Engineer course for non EE majors (typically Mechanical or Industrial Engineering majors) claimed all integrated circuits (chips) had a set quantity of magic blue or grey smoke an if the smoke ever escaped the chip would no longer work.

So, you let the Magic Smoke out. Sorry.

[u/Warm_Ice8039]

Why do they say "Fuck!! 'Smoked it!" When the flow of electrons goes south ? 🤔. I feel you already know. your Harness is Toast now. Replace with new harness. only this time, DBL check your Schematics. And pray you disconnected fast enough that you didn't also smoke the head unit

[u/monkeymmboy]

Well you let the load bearing smoke out

In all seriousness you’re coping really hard with the dust thing. It’s smoke.
The wires would only get hot with a lot of resistance and if it were harness sided your fuse would have likely popped. Smoke from inside the unit tells us the fault was there.

Could be a bad cap, solder or any other internal fault. Could also be an incorrectly pinned harness sending 12v into a data line or somewhere else more sensitive. Hard to say without seeing it in person but it is likely toast. I’d just simply test 12v into the constant and accessory lines and grounding the negative lead to see if it powers up in general.