Mystery issue blowing cig lighter fuse, kills blower motor and signals

This seems to be the mother of all issues I’ve ever had for a car. I’ve taken it to the best mechanic in town three times and they can’t figure out the root cause.

What happens is my turn signals and blower motor will stop working and the best cause found was the cig lighter fuse would blow. I would replace this fuse every few weeks and it has happened sooner. They verified no shorts or issues with the cig lighter itself. Thought maybe it was the alternator but it checked out as well.

The battery light on the dash will also flicker and the air bag dash light is always on along with check engine when started. Before I brought it in it started hard once or twice and felt like it was losing power or slow to accelerate. Wipers were slow too.

That assortment of seemingly-disparate symptoms would lead me to suspect a bad Body Control Module. That would not explain the starting problems or the acceleration problems, but you might want to start with the Body Control Module.

Did you recently buy this car?

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A direct short should blow the fuse immediately. Since this fuse holds up for the short term I suspect the fuse blowing is caused by something with an abnormally high current draw. The most obvious thing would be the cabin blower motor. Current draw on those can skyrocket with age and miles.

The shop should have checked the blower current draw with an ammeter. The blower can be faulty and still move plenty of air with no noise whatsoever.

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Update*

So after the fuse started blowing every single time I would drive, I got frustrated enough to take it to the dealership. The best they came up with was to replace a weak alternator (so they say) and for about two weeks this seemed to clear it up. But… As of this week I am back to square one as the fuse blows every time I drive again.

The only new information I have is that the blowing of the fuse is less random. It will either blow right when I start the car and most frequently, when I shift into reverse. Guess I should have taken the $800 I spent on diagnostics and an alternator to buy fuses in bulk lol.

Would this still be occurring even if I don’t have the AC/Heat on? The fuse always blows when it is off.

I’ve had the car for almost 4 years now and didn’t have this issue until the last two years. No major repairs or electrical work were completed during that time.

just for the heck of it. look inside the hole of the cigarette lighter for a
metal foreign object that could be blowing the fuse.

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I would put an accessory like a fan or light in the cig lighter socket and keep it on all the time. Then see if the light dims a bit or the fan slows down around the same time that the fuse blows. You could put one of those Volt meters in the cig lighter socket. Then keep an eye on it to see when the Voltage drops down.

Are the reverse lights on that circuit? Do you have a shorted reverse light? Maybe not fixing it and breaking open the top of a blown fuse to add PTC resetable fuse is the way to go! It’s hard to diagnose this kind of problem without randomly replacing things on that circuit until it goes away. You can splice in to wires and use a volt meter to see how much current is going through that wire to try to narrow down which thing is shorting out. After you find out how to reliably reproduce the problem of course.

I believe you have the fuse box cover inverted, viewing the diagram incorrectly. The cig lighter fuse only powers the lighter and/or power outlet.

The fuse across from the lighter fuse is labeled “Gauge”, this powers the instrument cluster, turn signals, charging system, air conditioning and reverse lights.

You probably have a short in the reverse light circuit, reporting the problem with the correct fuse will help in diagnosing the repair.

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