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46 votes
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Why don't cars have circuit breakers instead of fuses?

(1) Fuses are cheap. Really cheap. You can get a variety pack of 100 for $8 or so. Circuit breakers for 12V systems are available, but are not cheap (more like $10 each). My car has 40 or 50 circuits, ...
Jon Custer's user avatar
22 votes
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Should I replace fuses as a part of regular maintenance?

Fuses do not need to be replaced unless they have blown, so it's not a regular maintenance thing. In terms of checking them, depending on your vehicle, many only require a visual check to see if the ...
Rory Alsop's user avatar
  • 18.6k
22 votes
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40amp protection on 25amp rated wiring?

The maximum rating of 25A will be for continuous use. The 40A fuse is there to blow very quickly in a fault condition. If you look at this page https://en.wikipedia.org/wiki/American_wire_gauge 2mm² ...
HandyHowie's user avatar
  • 25.4k
17 votes
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How to test a bolted-in heavy duty 50a / 80a / 100a fuse with a multimeter without removing it?

Instead of Ohms checks of fuses I check for voltage with power on. Set your voltmeter to DC volts with the negative lead on the battery negative connector. With the positive lead test both sides of ...
Fred Wilson's user avatar
  • 11.6k
14 votes

How can a fuse drain a car battery?

It wouldn't be the fuse which is causing the power drain, but the circuit the fuse is there to protect. (This is the reason why the copied area you have posted has 5 "Not Helpful" votes against it.) ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
14 votes

Why don't cars have circuit breakers instead of fuses?

I don't have a definitive answer, but believe it is a combination of factors and boils down to the following: Cost: While both do the job of protecting circuits, a fuse runs you cents per unit, while ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
11 votes

Should I replace fuses as a part of regular maintenance?

As a general maintenance practice or a troubleshooting method without having a particular reasoned approach, no. If it's troubleshooting, testing the fuses on their exposed blade tips is equivalent. ...
DGM's user avatar
  • 141
10 votes
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Fault find blown cigarette lighter fuse

You have a short somewhere. The purpose of a fuse is to be the weak link in a circuit. If more current is running through a circuit than it was built to handle, a fuse will self destruct and break ...
raydowe's user avatar
  • 3,012
9 votes

Could corroded or incorrectly soldered battery teminals cause parasitic drain?

Have a look at this picture: From here. Corrosion (the green stuff) can conduct electricity. If one wire in that picture went to the battery positive terminal and the other went to the battery ...
JRE's user avatar
  • 201
9 votes

I have a distribution block buried under my center console. Would getting 12v from that line vs directly from the battery present any fire hazard?

The fuses are there to protect the wiring, the fuse needs to blow before the wiring gets hot. You say that you have a fuse at the battery end of the 4 gauge wire, so that wire is protected against ...
HandyHowie's user avatar
  • 25.4k
8 votes
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Indicators Not Working But Hazard Lights Working

Traced this problem to a fuse under the dashboard, located in the middle horizontal row right most fuse. Turns out this fuse is the indicator fuse and when this fuse is blown the indicators won't work ...
Chris Rutherfurd's user avatar
8 votes
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How to remove the 50 amp, 80 amp and 100 amp fuses from the positive terminal of a RAV4?

The fuse connection legs are through bolted on many of these higher amp rated fuses. To find out remove the black plastic cover below the fuses. If you find small nuts then they are the bolted in type....
Fred Wilson's user avatar
  • 11.6k
8 votes

Why don't cars have circuit breakers instead of fuses?

In addition to the other good answers: You'll see self-resetting circuit breakers in heavy-truck applications, which is a far more abusive environment, and prone to intermittent faults (esp. in ...
GB540's user avatar
  • 311
7 votes

How to test a bolted-in heavy duty 50a / 80a / 100a fuse with a multimeter without removing it?

If you can get to both sides of the fuse, see if you have power on each side. If you want to make sure, remove the battery terminal, and use an ohmmeter to measure the resistance between the battery ...
X-tech2's user avatar
  • 789
7 votes

Should I replace fuses as a part of regular maintenance?

Replace them all? No. As others have mentioned, they're either working or they're not. Test them with a multimeter or fuse tester. Be sure to look for "fusible links" in the wiring on a newer car, ...
Perkins's user avatar
  • 171
7 votes
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Golf 7 key stolen, which fuse to remove to disable car key reprogramming?

There is no fuse to remove that will disable immobilizer programming. You can how ever remove the fuse for the obd2 power. That will slow someone down since their tool would no longer be powered and ...
narkeleptk's user avatar
  • 3,780
6 votes
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Does a constant blown fuse always indicate a short?

If the fuse is blowing as soon as you perform an action it's a short to ground. Multimeter won't do much good in this situation. It'll come down to wiring diagrams and visual inspection of the ...
Ben's user avatar
  • 10.7k
6 votes

Seat heater fuse at 12V even when ignition is off?

There are three fuses for the seat heater system 1) Passenger fuse box: Fuse 20, 7.5 amp. Supplies Seat heater control unit. 2) Passenger fuse box: Fuse 5, 15 amp. Supplies relay power pin. 3) ...
Fred Wilson's user avatar
  • 11.6k
5 votes
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Need urgent help - car cut out and instruments frozen and will not start

I found the problem. I purchased breakdown cover and called the AA out on Sunday afternoon. They were very fast and the guy was incredibly helpful. He said that a fuse had blown, and checked the fuses....
George's user avatar
  • 6,545
5 votes

Fuse box location for 2006 Renault Scenic

I found manual here. The fuse box information is on pages 5.18 and 5.19, if you download the PDF: So it looks like it depends on whether your Scenic is a UK? model (steering wheel on the right) or a ...
Digital Trauma's user avatar
5 votes

How can a fuse drain a car battery?

You mention, "no draining electrics," can you say more about how you determined this? It's important because "a self-draining battery" requires something that is causing a load on the battery – ...
dlu's user avatar
  • 14.5k
5 votes
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Blew the fuse for the battery

That would work, but it's a very dangerous solution. The fuse exists in the circuit as a safety mechanism. If the circuit is flowing more power than it can safely handle, the fuse self destructs and ...
raydowe's user avatar
  • 3,012
5 votes

40amp protection on 25amp rated wiring?

I would suggest that you should find the source of the fault - probably in the wiring as you suggest as it could get worse and cause a fire (not the best thing in dense traffic with no place to go). ...
Solar Mike's user avatar
  • 34.6k
5 votes
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Could corroded or incorrectly soldered battery teminals cause parasitic drain?

The effect of corroded or poorly soldered battery terminals is responsible for excessive voltage drop, not parasitic current drain. They are not the root cause of the parasitic drain.
Zaid's user avatar
  • 39.2k
5 votes
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Given a fuse panel, which way should a fuse tap be facing?

If you are running an inline fuse (which you should), you put it on the power side. This is so you don't overtax the fuse you're tapping off of. To tell which is hot, pull the fuse and check each side ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
4 votes

How can a fuse drain a car battery?

What can drain your battery is Alarm system, Radio (memory), Remote control key (radio signal receiver), ECU, Clock... Can't imagine anything else. Even if you have all of this, they shouldn't drain a ...
Arturs Bolsunovskis's user avatar
4 votes
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A fuse slot has disappeared

So beneath that fuse is a wiring terminal. It's obvious that your terminal got pushed in so far that the fuse spades no longer touch anything. The good news is that everything is in there. The bad ...
zipzit's user avatar
  • 6,559
4 votes
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Dodge 2006 Grand Caravan fuse F6

Had the description a little wrong. Added how Chrysler describes the power outlet system with annotations in (). The power outlet on the instrument panel marked with a battery receives battery ...
Ben's user avatar
  • 10.7k
4 votes
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Missing fuses - is it OK?

The fuse box is designed for all vehicles and positions only used as needed for each vehicle. First check if those empty fuse slots have terminals in them, without terminals adding fuses does nothing....
Solar Mike's user avatar
  • 34.6k
4 votes

Connecting Fuse Tap to another Fuse location

Or will each appliance receive exactly what it asks for? Yes Conversely, if I connected this fuse tap and cigarette lighter instead to a lower amperage, like 10, what would happen if the cigarette ...
Moab's user avatar
  • 7,990

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