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2003 Forester XS w/Premium Package and 5MT tranny
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Discussion Starter #1
Our 94 Chevy pickup's 12-volt outlet doesn't work.

Which makes inflating the tires with my portable air compressor a real pain. I have to park Gemma, my 2004 Forester XS, near the truck to plug in my portable air compressor so I can inflate the tires when they're low on pressure.

Does anyone have any ideas on how to diagnose a non-working 12-volt outlet socket?

Thanks!

Caleb
 

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2012 Forester X Auto
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Have you checked your fuses?
Diagnosing electrical problems other than those visibly obvious requires some tools (a dc meter and a continuity tester) and the ability to read a wiring diagram.
An auto electric tech would start with a known (battery power) and follow the wiring to the outlet to find the point of failure, or start with the outlet first which may be faulty, and if it's good, then go through the wiring. That's how you diagnose it.

This should be one of the easier problems to diagnose and repair, and is pretty simple if you know what you are doing, but it sounds like you don't.
You are likely better off finding an auto electric guy who has a good reputation. They typically charge by the hour, but your problem should not take long to find.

Good luck.
 

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Sahuarita, Arizona USA 2018 Forester Limited
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It could simply be a fuse. Your owner's manual should show you the fuse location and amperage rating.

I can't tell you how many times I blew the 10 amp fuse in the 12volt dash outlet of my 2010 Forester while using a portable air compressor.
 

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2007 Forester Sports XT 4EAT
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@Caleb1534 assuming the fuses are good & the plug fits tightly into the socket, 12 volt outlets have a thermal fuse on the back that is known to blow if the outlet is overloaded or overheats.

Take a look at my post with a picture on this post on another thread. :wink:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
 

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2003 Forester XS w/Premium Package and 5MT tranny
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Discussion Starter #5 (Edited)
Have you checked your fuses?
Diagnosing electrical problems other than those visibly obvious requires some tools (a dc meter and a continuity tester) and the ability to read a wiring diagram.
An auto electric tech would start with a known (battery power) and follow the wiring to the outlet to find the point of failure, or start with the outlet first which may be faulty, and if it's good, then go through the wiring. That's how you diagnose it.

This should be one of the easier problems to diagnose and repair, and is pretty simple if you know what you are doing, but it sounds like you don't.
You are likely better off finding an auto electric guy who has a good reputation. They typically charge by the hour, but your problem should not take long to find.

Good luck.
I haven't checked the fuses yet, but not because I don't know 'anything' about what I'm doing. I just wanted to write a very concise post to start off this thread, then further explain the problem as needed.

Regarding the fuse for the 12-volt outlet, I simply haven't tried to find out which fuse links to that location yet.

My father has a voltmeter, and he knows how to check continuity, so I don't have a problem being able to figure out that aspect of diagnosing.

I spoke with a friend of mine yesterday who's a savant with diagnosing vehicle problems, and he gave me some really good ideas on how to figure out what's wrong with our truck's 12-volt outlet.

So no, I don't think I'll have a need to pay "an auto electric guy" to diagnose this problem.
 

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2003 Forester XS w/Premium Package and 5MT tranny
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Discussion Starter #6
It could simply be a fuse. Your owner's manual should show you the fuse location and amperage rating.

I can't tell you how many times I blew the 10 amp fuse in the 12volt dash outlet of my 2010 Forester while using a portable air compressor.
I am hoping it's just the fuse. I just need to discover which fuse goes to the 12-volt outlet and then check to see if it's blown.

Really? I've plugged in my portable air compressor into the 12-volt outlet in the cargo area of my 2004 Forester XS practically every week or two since February 2018 to air up my car's tires, and I've never blown the fuse associated with said outlet. However, I don't know what the amperage of that fuse is, or the power consumption of my air compressor vs. yours.
 

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2003 Forester XS w/Premium Package and 5MT tranny
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Discussion Starter #7
@Caleb1534 assuming the fuses are good & the plug fits tightly into the socket, 12 volt outlets have a thermal fuse on the back that is known to blow if the outlet is overloaded or overheats.

Take a look at my post with a picture on this post on another thread. :wink:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
Thank you, Bobby. I did see your post, so I'll definitely utilize that information if I need to progress to that stage of diagnosis.
 

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I haven't checked the fuses yet, but not because I don't know 'anything' about what I'm doing. I just wanted to write a very concise post to start off this thread, then further explain the problem as needed.
It's pretty hard to assess a person's knowledge level other than the way they pose a question. No insult intended.
A novice on their own is better served by having someone who knows what they are doing rather than creating a worse problem.

Regarding the fuse for the 12-volt outlet, I simply haven't tried to find out which fuse links to that location yet.
Well, that's your first step... So basically you did absolutely nothing other than complain. That sounded pretty novice to me. Thus my response.
There is usually a map inside or near the fuse pocket.. if not you can probably find one in the back of the owners manual.
My father has a voltmeter, and he knows how to check continuity, so I don't have a problem being able to figure out that aspect of diagnosing.
Regardless of a person's experience, without a wiring diagram, no one would know what to check. There are more than a few circuits under the hood.
I spoke with a friend of mine yesterday who's a savant with diagnosing vehicle problems, and he gave me some really good ideas on how to figure out what's wrong with our truck's 12-volt outlet.
So no, I don't think I'll have a need to pay "an auto electric guy" to diagnose this problem.
How nice for you.
I guess I should have said, have your father see if he can fix the problem or if not, have your friend look at it, since he's an expert...

Maybe you could enlighten the forum with "some really good ideas on how to figure out what's wrong with our truck's 12-volt outlet".
 

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Sahuarita, Arizona USA 2018 Forester Limited
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I am hoping it's just the fuse. I just need to discover which fuse goes to the 12-volt outlet and then check to see if it's blown.

Really? I've plugged in my portable air compressor into the 12-volt outlet in the cargo area of my 2004 Forester XS practically every week or two since February 2018 to air up my car's tires, and I've never blown the fuse associated with said outlet. However, I don't know what the amperage of that fuse is, or the power consumption of my air compressor vs. yours.
On my 2010, the dash 12volt outlet was only a 10amp circuit but the console and cargo area outlets were 15amp. I never blew a 15amp circuit fuse but blew the 10amp several times with my portable air compressor before realizing the other outlets were 15amp. I've also had the dash outlet's 10amp fuse blow while a passenger was using a portable DVD player.
 

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@ForesterBill - Yep. A few amps can make a big difference.
No idea on a Chevy pickup, but an overload of some kind is the typical reason for a blown fuse. Or a short.
My console power point just blew a fuse... It was powering my cell phone charger and I also had a little LED flashlight always being charged.
A minimal load, but the flashlight's negative connector was loose and shorted to positive - It blew my 20 amp fuse for the console. (Mine didn't have a 15)
Of course it also blew the 10 amp fuse for the dash power when I tried the charger there (before I found the LED light issue). Another mystery solved.

One of the weirdest I had was a mouse nest in my under hood fuse box.. It only affected the power outlets, but all three in the car failed at the same time..
I probably would not have found it so soon, but I opened up the box to get the fuse puller out...

When it comes to failed auto electrics, it can be a bad switch, a fried relay, a rat chewed wire, a bad socket, an oxidized connector, a bad ground.. or ….
;-)
 

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@Caleb1534

I see you posted the same question on another forum and were told "it is the same fuse that powers the horn if your horn works then replace the power socket"

So, does your horn work?
 

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2003 Forester XS w/Premium Package and 5MT tranny
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The horn does work. So does the chime that sounds when the key in the ignition.

So, the power socket itself must be the problem, whether the wiring that's connected at the one end or something about the socket itself.
 

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Sahuarita, Arizona USA 2018 Forester Limited
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@ForesterBill - It blew my 20 amp fuse for the console. (Mine didn't have a 15)
I stand corrected. My 2010 had a 20 amp fuse for the console and cargo power outlets. I got it confused with the amperage of my portable air compressor which was 15 amp.
 

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Discussion Starter #14
First off, I sincerely regret and wish to apologize for the way I responded to your initial post. Not to excuse myself, but I was in a bad mood already for several other reasons when I read your post. I took offense at the way you interpreted my first post when the real problem was my indistinct communication with you and the other forum members. Typically, I write in a very detailed and complete manner, so that post was out of character for me. I wrote it last Saturday very quickly and briefly, trying to elicit a quick response from y'all so that I could hopefully fix our truck's 12-volt outlet that day. The ironic thing is that I ended up not having enough time that day to even work on it at all. With that brief, unclear post, I was taking the forum members' knowledge for granted, hoping they would respond with good ideas despite my indistinct communication. For that, I also apologize to everyone here.

It's pretty hard to assess a person's knowledge level other than the way they pose a question. No insult intended.
A novice on their own is better served by having someone who knows what they are doing rather than creating a worse problem.
Agreed. None taken (now...). Technically, I am still very much a novice concerning the diagnosis of vehicle problems. However, compared to my level of knowledge 3 years ago, I do know much more now about vehicle repair, maintenance, and problem diagnosis than I did then. But I still don't know very much in the big scheme of things. That's why I strongly rely on other people who are more knowledgeable than me on these topics. For example, I have a friend who's a Subaru Master Mechanic (he's been a mechanic for over 20 years). He's been an invaluable source of Subaru-related information. I can't even tell you how many times I've texted him with questions about both of my 2004 Subaru Foresters (Sylvia and Gemma). I've learned so much from him about Subarus. Second, I do have a friend who can best be described as a 'savant' with vehicle issue diagnosis. He's also been an invaluable source for helping me figure out things about our 2001 VW Beetle and our 1994 Chevrolet K1500 Silverado Z71.

Well, that's your first step... So basically you did absolutely nothing other than complain. That sounded pretty novice to me. Thus my response.
There is usually a map inside or near the fuse pocket.. if not you can probably find one in the back of the owners manual.
I did know that I should check the fuse first. I just hadn't done that yet. You're right; my initial post did come across as only a complaint. That's certainly not the way I intended for it to come across; however, due to my incompleteness of communication, that's exactly the way it sounded. Thank you for sharing those details with me about checking the fuse.

Regardless of a person's experience, without a wiring diagram, no one would know what to check. There are more than a few circuits under the hood.
You're absolutely right on that. Taken as a whole, vehicle wiring is extremely complicated.

How nice for you.
I guess I should have said, have your father see if he can fix the problem or if not, have your friend look at it, since he's an expert...

Maybe you could enlighten the forum with "some really good ideas on how to figure out what's wrong with our truck's 12-volt outlet".
My father does know more than I about electrical stuff and wiring that I do, but he doesn't know much about vehicles.

Let me see if I can recall what my friend said...

First, he asked if I had checked the fuse.

Second, he told me how to use a voltmeter to see if the outlet itself was the problem, or if the power supply was the problem. He said to touch the negative tip to a grounding source (something metal near the outlet), then touch the positive tip to the terminal on the inside of the outlet, at the bottom of it. He then said that there's a place to perform the same procedure at the rear of the outlet, up under the dashboard. If the outlet has power where the wires connect it to the power source, but not inside it, then the outlet itself is bad and should be replaced.

Third, he told me something about checking wiring under the hood, but I don't remember those details anymore.
 

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@Caleb1534,

It's all good.
I'm glad you are getting some assist.
One thing I would add is that there can occasionally be more than one issue to any given problem, and when that happens, it can be really confusing.
When you think you've found the problem (and you did) and it still doesn't work, it doesn't mean you haven't improved the situation.
It just means there was more than one cause.
As @ForesterBill brought up, something caused your fuse to blow in the first place.
If it was your plug in compressor due to too much current draw, it will probably happen again.
For testing purposes, I would suggest you use a low power item that you know works first.
Again, good luck.
 

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A lot of vehicles have a lighter fuse that is lesser amps than some air compresses draw. If you plan to continue to power the air compressor with the truck, hard wire a new power outlet with adequate wire and fuse ratings, and mount it close to the battery.
It sounds like you have knowledgeable people to guide you. Life is a learning adventure. Youth is great, experience is great. One goes away as you gain the other. Enjoy where you are.
 

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2003 Forester XS w/Premium Package and 5MT tranny
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Discussion Starter #17
A lot of vehicles have a lighter fuse that is lesser amps than some air compresses draw. If you plan to continue to power the air compressor with the truck, hard wire a new power outlet with adequate wire and fuse ratings, and mount it close to the battery.
It sounds like you have knowledgeable people to guide you. Life is a learning adventure. Youth is great, experience is great. One goes away as you gain the other. Enjoy where you are.
The fuse that is connected to the 12-volt power outlet is also connected to the interior lights; this fuse is a 20-amp fuse, and my portable air compressor uses 15 amps.

However, thank you for your suggestion!

I absolutely enjoy learning, and I do have more than one knowledgeable person that I can consult on the topic of vehicles. Youth and experience are indeed inversely related; I see that more clearly now, being in my mid-twenties. I do intend to do my best to be content in the state that I'm currently in. To quote what the apostle Paul said in one of his epistles (Philippians) in the New Testament: "For I have learned, in whatsoever state I am, therewith to be content."
 

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@Caleb1534 - Sounds like you have a good attitude.
Per previous posts, it sounds like you also have the issue isolated to the power socket.
I don't know about the truck, but on some vehicles getting access to that power point can be a royal pain... Like on a Forester..
If this is the case, @sinbad 's suggestion of putting in a new plug somewhere else might be easier.

You could also rig up a harness maybe with an old set of jumper cables and a connect them to a fused power port, so you wouldn't have to change anything on the truck..

Actually, I'm thinking I might build one myself in case someone needs power (or air) too far away from my vehicle.. it could come in handy.

Merry Christmas!
:laugh:
 

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these cheap plug in oil less compressors ,in general do not last a long time, usually, as they wear , they tend to cause greater internal friction,;,, that draws more current, it may be the compressor that is bad, not the socket, easily tested with a volt meter, and there are adapters bought or home made to allow a plug socket to attach via clips directly to the battery, so that you run the engine and draw directly from the battery terminals, much better than a inside socket usually ................ imo, if you are airing up the tires several times a week it is time for new tires, tubes, or examine the wheels to see if they are leaky and why - many subaru models are relative high maintenance , especially when older models,;.. and owners either must have money to hire repairs, or be willing to take the time and effort to do for themselves
 

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Discussion Starter #20
@Caleb1534 - Sounds like you have a good attitude.
Per previous posts, it sounds like you also have the issue isolated to the power socket.
I don't know about the truck, but on some vehicles getting access to that power point can be a royal pain... Like on a Forester..
If this is the case, @sinbad 's suggestion of putting in a new plug somewhere else might be easier.

You could also rig up a harness maybe with an old set of jumper cables and a connect them to a fused power port, so you wouldn't have to change anything on the truck..

Actually, I'm thinking I might build one myself in case someone needs power (or air) too far away from my vehicle.. it could come in handy.

Merry Christmas!
:laugh:
Actually, it turns out that the fuse that powers both the 12-volt power socket and the interior lights was removed several years ago. I now remember why. If I leave that fuse plugged in, then the interior lights do NOT turn off when both doors are shut and the engine is turned off. Thus, there's some type of electrical problem with that circuit.

However, I can now add air to the truck's tires without having to use my Forester to do it. That makes me very happy.

Isolating the problem with that electrical circuit is not a pressing issue, as I can simply keep that fuse disconnected except when I need to use my portable air compressor (which is exactly what I've been doing).
 
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