There are primarily three reasons why the 12V power outlet in a Toyota Prius stops working.
In this article, we have discussed those three reasons in depth and their possible fix.
After reading this article, you will be able to pinpoint the issue and also be able to fix it yourself within a few minutes.
The Fuse Is Out
There are two fuse boxes in the Toyota Prius. One is in the engine compartment, and another one is below the steering wheel column.
Both the cigarette lighter and 12V power outlet fuse is below the steering wheel.
One of the primary reasons for the non-working 12V power outlet is that the fuse has blown out.
There are many reasons why fuses go out. But the main reason is connecting electrical equipment that draws more power than the 12V power outlet can provide.
Typically, the 12V outlet in the Toyota Prius can provide a maximum of 240W safely.
If we connect any electrical equipment such as a portable air inflator, portable heater, or vacuum cleaner, it can blow the related fuses as these types of electrical equipment sometimes draws more power than mentioned.
Here is a picture of the fuse box.
A small plastic cover covers the fuse box. If you pull hard enough, it will come out.
On the back of the cover, there’s a diagram of which fuse does what. The following image shows the fuse diagram.
Two fuses control the two 12V power outlets independently.
Depending on Toyota Prius’s model (LE, SE, XLE, etc.), one fuse could be 15A, another fuse could be 20A, or both could be 20A.
Pull out each fuse and inspect whether the fuse is blown or not. The following image shows an image of a blown fuse (B).
If the fuse is blown, replace it with a working fuse.
You can purchase a fuse at a reasonable price from Walmart, NAPA auto centers, Advance Auto parts, or any other auto repair shops.
Changing the fuse on the Toyota Prius is an easy DIY project; anyone can do it, and it takes 2 minutes.
However, if you don’t feel comfortable changing the fuse, we suggest you take your Prius to the nearest auto mechanic shop. You don’t need to visit a Toyota Service center to fix it.
Typically, changing the 12V fuse in a Prius would cost around $40 depending on location, but the price could go higher.
To protect this fuse from future damage, we highly recommend not to connect the electrical equipment that caused the fuse to blow out.
Please remember that these 12V power outlets in the Toyota Prius can provide a maximum power of 240W. However, to be on the safe side, we highly recommend not to connect any electrical equipment that draws more than 200W.
Many camping blankets, heaters, and air inflators sometimes draw more power than the label shows.
If you looked in the fuse box under the steering wheel column in your Prius and found that no fuse is blown and everything is normal. However, the 12V power outlet is still not working; the power accessory relay is probably damaged.
The power accessory relay controls all the accessory power inside your Prius. The relay typically is off when the key is off, but when we turn the key to “Acc” position, it turns on and provides power to accessory outlets inside our Prius.
However, if this relay gets damaged due to a surge current or aging, the 12V power outlet will not work.
We can confirm whether the relay is causing the 12V not to work even without opening the relay.
Open the fuse box cover under the steering wheel. Each fuse has a small wire exposed. Take a voltmeter and check the 12V controller fuse terminal’s power.
If the fuse isn’t getting power, it proves that the accessory relay isn’t working.
This Accessory Relay is also under the steering wheel column. However, getting to this relay is hard compared to the fuse box.
The following image shows the accessory relay.
You need to open some 10mm nuts and plastic cover to access this relay.
Once you open the plastic cover of this relay, pull it out. And replace it with a similar type of relay.
However, if you don’t feel like doing this alone, we recommend taking your Prius to your trusted auto mechanic shops or the Toyota Service Center.
Typically it would cost $80-$100 to change the fuse with parts and labor. But depending on the location, the cost could be higher.
Bad 12V Socket
If you found that both the fuse and accessory relay are working fine, the probability is the 12V power socket has gone bad in your Toyota Prius.
Even though it’s rare, it does happen.
We suggest you open the center console and check the 12V socket. Some older Prius models have another fuse integrated with the 12V power socket in the center console.
Change the 12V socket if you notice any electrical damage. You can buy spare parts from the Toyota service center or a salvage yard.
Sometimes, the 12V male port on the electronics end can also not properly sit in the socket.
Please look inside the port to see whether there is any debris. Debris can prevent proper electrical connections.
If all the three diagnoses mentioned above fail to fix your 12V power socket in your Toyota Prius, we highly recommend you take your Prius to a trusted auto mechanic shop.
There’s something wrong in your Prius that only a professional auto mechanic can fix.
However, before you take your Prius, please do the following checks to isolate your issue further.
- Check all the 12V power outlets
- Check all the USB ports
- Check all the Accessory lights on the dashboard
- Check horn
- Check Radio
If everything is working except for the 12V power outlet, then the wire behind the power outlet may get damaged and need fixing.