Fuse (automotive) - AbsoluteAstronomy.com

Automotive fuses are a class of fuses

Fuse (electrical)

In electronics and electrical engineering, a fuse is a type of low resistance resistor that acts as a sacrificial device to provide overcurrent protection, of either the load or source circuit...

used to protect the wiring and electrical equipment for vehicles. They are generally rated for circuits no higher than 24 volts direct current

Direct current

Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

, but some types are rated for 42-volt electrical system

42-volt electrical system

In automobiles, a 42-volt electrical system was a proposed electrical power standard in the late 1990s intended to allow more powerful electrically driven accessories, and lighter automobile wiring harnesses...

s. They are occasionally used in non-automotive electrical products.

Blade type

Blade fuses (also called spade or plug-in fuses), with a plastic body and two prongs that fit into sockets, are mostly used in automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

s. Each fuse is printed with the Rated Current in Ampere

Ampere

The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...

s on the top. These types of fuses come in four different physical dimensions: low-profile mini (APS), mini (APM / ATM), regular (APR / ATC / ATO), and maxi (APX) heavy-duty. Unofficially, the APS fuse is sometimes called "micro" since the term means smaller than mini. Regular blade type fuses, also known as standard fuse, were developed in 1976 for low-voltages use in motor vehicle

Motor vehicle

A motor vehicle or road vehicle is a self-propelled wheeled vehicle that does not operate on rails, such as trains or trolleys. The vehicle propulsion is provided by an engine or motor, usually by an internal combustion engine, or an electric motor, or some combination of the two, such as hybrid...

s. The mini fuses were developed in the 1990s. Blade type fuses can be mounted in fuse blocks, in-line fuse holders, or fuse clips.

Size groups

Blade Size	Blade Group	Common Ratings
Low-Profile Mini	APS	2, 5, 7.5, 10, 15, 20, 25, 30
Mini	APM, ATM	2, 3, 4, 5, 7.5, 10, 15, 20, 25, 30
Regular	APR, ATC, ATO	1, 2, 3, 4, 5, 7.5, 10, 15, 20, 25, 30, 35, 40
Maxi	APX	20, 25, 30, 35, 40, 50, 60, 70, 80, 100, 120

Where space permits, a miniature circuit breaker

Circuit breaker

A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow...

is sometimes used to replace a blade-type fuse in the same fuse holder.

Color coding

Blade fuses use a common coloring scheme for the low-profile mini / mini / regular size fuses, and a partial color similarity with the maxi size fuses. The following table shows the commonly available fuses for each size group.

Color	Ampere Ampere The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...	Low	Mini	Reg	Maxi
DarkBlue	0.5	.	.	.	.
Black	1	.	.	X	.
Gray	2	X	X	X	.
Violet	3	.	X	X	.
Pink	4	.	X	X	.
Tan	5	X	X	X	.
Brown	7.5	X	X	X	.
Red	10	X	X	X	.
Blue	15	X	X	X	.
Yellow	20	X	X	X	X
Clear	25	X	X	X	Gray
Green	30	X	X	X	X
BlueGreen	35	.	.	X	Brown
Orange	40	.	.	X	X
Red	50	.	.	.	X
Blue	60	.	.	.	X
Amber/Tan	70	.	.	.	X
Clear	80	.	.	.	X
Violet	100	.	.	.	X
Purple	120	.	.	.	X

Bosch type

Bosch

Robert Bosch GmbH

Robert Bosch GmbH is a multinational engineering and electronics company headquartered in Gerlingen, near Stuttgart, Germany. It is the world's largest supplier of automotive components...

type fuses (also known as torpedo, ATS, or GBC type fuses) are used in old (often European) automobiles. The physical dimension of this type of fuse is 6x25 mm with conical ends. Bosch type fuses usually use the same color coding for the rated current. The DIN

Deutsches Institut für Normung

is the German national organization for standardization and is that country's ISO member body. DIN is a Registered German Association headquartered in Berlin...

standard is 72581/1. The size of the fuse is: 6x25 mm.

Color coding

Color	Ampere Ampere The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...
Yellow	5
White	8
Red (or Green)	16
Blue	25
Grey	40

Lucas type

Lucas type fuses are used in old British-made or assembled automobiles. The physical length of this ceramic type of fuse is either 1 inch or 1.25 inch, with conical ends. Glass tube fuses have straight ends. Lucas type fuses usually use the same color coding for the rated current. Lucas fuses have three ratings; the continuous current they are designed to carry, the instantaneous current at which they will fuse, and the continuous current at which they will also fuse. The figure found on Lucas fuses is the continuous fusing current which is twice the continuous ampere rating that the system should be using; this can be a source of confusion when replacing Lucas fuses with non Lucas fuses. The Lucas 1/4" diameter glass tube fuse have a different physical length as compared to the standard US item. The Lucas 1/4" diameter glass tube fuse is 1 and 5/32" [~29.4mm] long, while the US standard 1/4" glass tube fuse is 1 and 1/4" [~32.0mm] long.

Color coding

Color	Continuous ampere Ampere The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics... (=Rated Current)	Instantaneous fusing ampere Ampere The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...	Continuous fusing ampere Ampere The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...
Blue	1.5	3.5	3
Yellow	2.25	5	4.5
Red on Yellow	2.5	6	5
Green	3	7	6
Nut Brown	4	10	8
Red on Green	5	12	10
Green on Black	5	12	10
Red on Brown	6	14	12
Light Brown	7.5	18	15
Pink	12.5	30	25
White	17.5	40	35
Purple on Yellow	25	60	50
Yellow on Red	30	75	60

Glass Tube type

North-American built automobiles up to 1981 had electrical systems protected by glass cartridge fuses rated 32 volts and current ratings from 4 amperes to 30 amperes. The fuse dimensions and characteristics are standardized by the Society of Automotive Engineers standard J554. All fuses are 1/4 inch diameter, and the length varies according to the rating of the fuse. A 4 Amp fuse is 5/8 of an inch long, a 20 Amp fuse is 1 1/4 inches long, and a 30 amp fuse is 1 7/16 inches long.

Limiter type

Limiter fuses consist of a metal strip from a lock plate, for currents over 40 amperes. Frequently, these are used in close proximity to starter battery

Car battery

An automotive battery is a type of rechargeable battery that supplies electric energy to an automobile. Usually this refers to an SLI battery to power the starter motor, the lights, and the ignition system of a vehicle’s engine...

fuse boxes. They are used also in electric vehicles, e.g., in forklift truck

Forklift truck

A forklift is a powered industrial truck used to lift and transport materials. The modern forklift was developed in the 1920s by various companies including the transmission manufacturing company Clark and the hoist company Yale & Towne Manufacturing...

s. Because strip fuses require the use of tools for replacement they are therefore legally considered non-serviceable components for end-users.