This is a shot of the fuse panel that I used, with fuses and the cover installed.

It has standard male blade terminals underneath to which you connect the power wire in to the fuse and the power wire after the fuse, for each of this six circuits / fuse slots.

There are may other small fuse panels that you could use, including this one that has the blade terminals on the side rather than underneath.

The main criteria is that it fit into the very limited space available. Personally I don;t particularly like this style because the terminals on the sides are pretty exposed.

This is a typical automotive style relay. This one with a built-in mounting tab.

The circuit schematic is printed on the top, which we shall look at momentarily.

Not also that the specification (current carrying capacity) is also printed on it. This is where it says:

NO: 40A / NC: 30A 12VDC

This means that its capacity is 40 amps through the "normally open (NO)" circuit, and 30 amps through the "normally closed (NC)" circuit, both ratings at 12 volts direct current (12VDC) - which is the voltage your car and ATV work on.

We;; look at what the "normally open (NO)" circuit and the "normally closed (NC)" circuit are shortly.

Another view of the typical 40A automotive relay, showing the terminals to which the wiring is attached.

Note that this one also has the circuit diagram stamped on it - this time on the side.

This style of relay is also commonly known as a "Bosch Relay", so named after the company that popularized its use.

If you look carefully at the bottom, beside the blade terminals, you will see small numbers stamped next to each terminal. This is then umber of the terminal, and each number corresponds to a number on the circuit diagram.

This is the schematic diagram for a single pole, single throw (SPST) switch, This is the simplest kind of switch. An example would be a simple on-off switch. It controls a single circuit (so "single pole") and there is only one switch position that results in a circuit connection - the "on" position (so "single throw").

Of course, this switch has two control positions: "on" and "off", so the number of throws is one less than the number of control positions

In the diagram at left, the switch is seen in the "off" or "open" position - i.e. there is no circuit completed.

This is an example of an actual SPST switch.

It is single pole - so It controls a single circuit (turns something ON or OFF)

It has a single throw - so there is only one switch position (ON) that results in a completed electrical circuit.

It has two control positions - ON and OFF

This is the schematic diagram for a single pole, double throw (SPDT) switch, This is also a simple and very common kind of switch. An example would be a selector switch where the user selects between two positions - a light switch with "HI" or "LOW" positions is an example. It controls a single circuit (so "single pole") and there are two switch position that can results in a circuit connection - the "HI" position or the "LOW" position - so "double throw").

This switch could have two or three control positions: It could be just "HI" and "LOW" and therefore always be in one or the other, or it could also have an intermediate "off" position, so depending on the actual switch design the number of throws could be either be the same as the number of control positions (in the case of "HI" or "LOW") or one less than the number of control positions (in the case of "HI" "OFF" "LOW")

In the diagram at left, the switch is seen in the "HI" position.

This is an example of an actual SPDT switch.

It is single pole - so it controls a single circuit (turns something to HI, OFF, or LOW)

It is double throw - there are two positions (H and L) that result in a completed electrical circuit.

It has three control positions - H, OFF, and L

This is a schematic diagram of the five blade terminals on an SPDT relay.

They are always in this orientation and always the same, regardless of the brand or rating - making them interchangeable.

The terminals are as follows:

• terminal 86 is connected to the control signal 12V+ 
• terminal 85 is connected to ground
• terminal 30 is the high-current power supply line 12V+
• terminal 87a is the normally closed connection. 12V+ current is available here when no current is applied to terminal 86.
• terminal 87 is the normally open connection. 12V+ current is available here when 12V+ current is applied to terminal 86.

This is a schematic of an SPDT relay.

The electromagnetic coil is illustrated in the middle. When there is no voltage across terminals 85 and 86, no current flows through the coil, therefore no magnetic field is produced, and the relay's movable contact (connected to terminal 30) is held, by spring tension, against the electrical contact which is connected to terminal 87a (the normally closed contact).

In other words, when no voltage is applied to the relay coil, terminal 30 is connected to terminal 87a, and therefore high current 12V DC is available at terminal 87a, as shown in this schematic

When 12 volts is applied to the relay coil (terminals 85 and 86), current flows through the coil, a magnetic field is created and thus the movable contact (connected to terminal 30) is pulled by the magnetic field into contact with the electrical contact which is connected to terminal 87.

In other words, when voltage is applied to the relay coil, terminal 30 is connected to terminal 87, and therefore high current 12V DC is available at terminal 87, as shown in this schematic.

This is a 4-terminal SPST relay. It's the same as the SDT, except that there is no terminal 87a, so no contact where 12V DC is available when the relay is not energized (i.e. when the relay isn't getting current to terminal 86)

Note the schematic is still stamped on the side, and that the terminal pin-out is exactly the same as the SPDT relay already shown except terminal 87a (the centre one) is missing .

Schematic of SPST relay in de-energized (i.e. off) position.

No current flows through the coil, the spring holds the moveable contact open, no current available at terminal 87.

Essentially it's just a fancy electrical switch in the OFF position.

Schematic of SPST relay in energized (i.e. on) position.

Current flows through the coil from terminal 86 to 85, the resulting magnetic field holds the moveable contact closed, terminals 30 and 87 are connected, high current available at terminal 87.

Essentially it's just a fancy electrical switch in the ON position.

They are available pre-wired with female terminals and a multicoloured pigtail, like this one.

The drawback to this style is that you are limited to the wire size use, which is normally a max of 14 gauge.

Incidentally, the wire colours match a common standard (same colours indicated in the schematics above).

...and crimp on the required female terminals, like this one, using the wire gauge of your choice.

So let's move on to the installation and see how that is done.

My Grizzly was delivered with a winch installed by the dealership, so here you can see:

A - Location where the dealership spliced into the stock 12V+ wire (brown with blue stripe) that is hot when the key is turned on.

B - The two red wires spliced into the brown/blue wire that carry power to the handlebar winch control and the fender-mounted remote winch control socket.

C - Winch power wire - connects battery (+) terminal to winch circuit breakers

D - Winch circuit breakers

E - Winch power wire that connects the circuit breakers to the winch motor.

There are two wire bundles that enter the area under the hood from the right front fender.

One has two wires and a white connector - it is the wiring for the factory 12V+ accessory socket mounted on the fender.

The other has three wires and a larger grey connector. The wires are red, brown with green stripes, and brown with blue stripe. It is this last one, brown with blue stripe, that we are going to tap into to provide the control voltage to the relay (terminal 86).

As I mentioned, the dealership had already tapped into this wire when installing my winch. If you don't have such an arrangement, you can just carefully strip a little of the insulation off one side of the brown/blue wire to provide a solder connection for the relay control wire.

I wasn't thrilled with the way the dealership had spliced directly into this wire for the winch controls and left then un-fused, so I decided I would remove these two connections and instead connect the two red winch-control wires to my fuse panel once installed.

So I desoldered the winch control wires, covered one of the insulation gaps with liquid electrical tape (A), and then soldered on a new 16 gauge red control wire (B) that will turn the new relay on and off.

This wire will only carry less than an amp (it takes well less than an amp to activate the relay), and will be fairly short as well, so virtually any gauge wire 22 or above will do.

...using a tool known as a barrel crimper. You can get these fairly cheaply at auto parts stores, tool specialty shops, and online.

However, if this is the only relay you will ever install, you can crimp on the terminals with patient and careful use of small needle-nose pliers, possibly backed up with a dab of solder.

Once the terminal is crimped on, you insert it into the back of the relay socket and it clicks in place. The terminals have a little tab that prevents them from being pulled back out.

Make sure you insert the terminal into the correct numbered slot in the relay socket!

I then did the same for the connections to terminal 85 and terminal 30.

The other end of the wire connected to terminal 85 was then connected to the battery hold-down stud with a ring terminal to provide the relay ground.

The other end of the wire connected to terminal 30 was then connected to the winch circuit breaker bolt with a ring terminal to provide the relay high-current power.

I used 8 gauge wire for this connection.

For the final relay connection, terminal 87, I crimped a relay terminal to another piece of 8 gauge wire and inserted this in the relay socket.

Then, on the other end of this 8 gauge wire, I spliced six individual wires and connected each to one of the connections on the fuse panel using a female spade connector.

Relay switched mini fuse panel all wired up.

A - Relay socket

B - 40 amp relay

C - Winch circuit breakers

D - 6-slot mini fuse panel

Here are the installed positions of the new components.

The relay is zip tied down to the existing winch wiring.

The new fuse panel fits neatly up under the left side panel.

And the hood snaps right back in place!

Now I have a 6-slot mini fuse panel ready to accept all my electrical accessories as I add them, all controlled by the main key switch through the relay.