Auxiliary Fuse Relays
IF THE IMAGE IS TOO SMALL, click it.
Adding fuses this way minimizes the added load on the factory ignition switch contacts, and allows a wide variety of configurations. Points where new wire is connected are shown in lime green.
Both new SPDT control switches & relays are not required - they're shown, but optional. If all new accessories are to be controlled by 1 ignition switch position, then only that relay is required. If the ability to turn those accessories OFF while the ig.sw. is ON is not necessary, then the control switch can be omitted, and that ig.sw. feed can be connected directly to the control relay's 86 terminal.
The 1A fused battery feed to the SPDT control switches is optional to allow the accessories to be forced on temporarily without the key. Doing so will NOT power the factory circuits - only the new ones. For this function, a switch with a momentary position is recommended so the circuits aren't accidentally left on to drain the battery. Look for a switch marketed as "On-Off-(On)" or "On-Off-Mom"; some retailers may identify it as an SP3T/SPTT switch, and that configuration will work, too, simply by NOT connecting anything to the center throw. If this function is NOT required, an SPST switch is sufficient.
The wire gauges noted are the recommended MAXIMUM (lowest gauge number); wires 2~6 gauges smaller (higher number) will work, provided the current draw on each is considered & calculated. The fusible link wire should always be 4 gauge numbers smaller (higher) than the wire going to the new fuses. The fan fuse should actually be connected to the new fusible link closer to the battery - it's only drawn this way to keep the diagram more organized.
The fuse block & subsequent relays can be in the cabin or under the hood, provided wires that pass through body panels do not chafe or short. Fuses must be sized to protect the new wiring between the new fuse & the new accessory; wiring must be sized for the max current draw of all the accessories on that particular wire. Fuses & wires must not exceed the current capacity of the fuse block terminals, which is why the e-fan is shown separate - it's too high a draw for most aftermarket fuse blocks, and many OE (JY).
The SPST dash switches carry NONE of the accessories' loads, so they can all be very-low-current (inexpensive) switches. All the accessory load goes through the relays at the far Right of the diagram.
"Low-draw" means any accessory supplied with a 5A fuse or smaller. The total load on either control relay should not exceed ~25A.
"High-draw" means any accessory with a peak draw of 5~40A (60~500W). For 25-40A loads, be sure to use a 40A relay.
"Internal switch" means any primary control switch included with, attached to, or built into an electrical accessory, including a thermocouple chiller/cooler's external selector switch.
"RD" means radar detector. It's grouped with "engine-on" accessories because it's not needed if the vehicle is parked. The stereo & CB could be used while parked, so they're "key-on" accessories.
"Winch control" means a hard-wired dash switch to control a medium or large electric winch's built-in relays, or electric solenoid valves for a hydraulic winch. It does NOT mean the high-current inline control switch used on some very-light-duty (ATV) winches. ANY electric winch's main power wire should be connected directly to the starter relay's battery stud. I chose to connect this to the engine-running circuit for several reasons:
1) a winch draws a LOT of current, so the alternator needs to be putting out to help it run, and so the battery isn't drained too low to start the engine later;
2) the engine & drivetrain should always be used to help the winch move the vehicle, and the steering wheel needs to be unlocked (on vehicles with key-steering interlock);
3) when the key is removed, the dash switch is disabled, so someone inside the vehicle without the key can't easily or accidentally operate it;
4) if the winch is required with the key off, the SPDT control switch can be moved to the battery override position temporarily.
Those are all just suggestions based on best practices. This diagram is easily adaptable to almost any safe configuration.
This diagram was created from this set of symbols using MSPaint:
![auxfuserelayeb.jpg Auxiliary Fuse Relays
IF THE IMAGE IS TOO SMALL, click it.
Adding fuses this way minimizes the added load on the factory ignition switch contacts, and allows a wide variety of configurations. Points where new wire is connected are shown in lime green.
Both new SPDT control switches & relays are not required - they're shown, but optional. If all new accessories are to be controlled by 1 ignition switch position, then only that relay is required. If the ability to turn those accessories OFF while the ig.sw. is ON is not necessary, then the control switch can be omitted, and that ig.sw. feed can be connected directly to the control relay's 86 terminal.
The 1A fused battery feed to the SPDT control switches is optional to allow the accessories to be forced on temporarily without the key. Doing so will NOT power the factory circuits - only the new ones. For this function, a switch with a momentary position is recommended so the circuits aren't accidentally left on to drain the battery. Look for a switch marketed as "On-Off-(On)" or "On-Off-Mom"; some retailers may identify it as an SP3T/SPTT switch, and that configuration will work, too, simply by NOT connecting anything to the center throw. If this function is NOT required, an SPST switch is sufficient.
The wire gauges noted are the recommended MAXIMUM (lowest gauge number); wires 2~6 gauges smaller (higher number) will work, provided the current draw on each is considered & calculated. The fusible link wire should always be 4 gauge numbers smaller (higher) than the wire going to the new fuses. The fan fuse should actually be connected to the new fusible link closer to the battery - it's only drawn this way to keep the diagram more organized.
The fuse block & subsequent relays can be in the cabin or under the hood, provided wires that pass through body panels do not chafe or short. Fuses must be sized to protect the new wiring between the new fuse & the new accessory; wiring must be sized for the max current draw of all the accessories on that particular wire. Fuses & wires must not exceed the current capacity of the fuse block terminals, which is why the e-fan is shown separate - it's too high a draw for most aftermarket fuse blocks, and many OE (JY).
[url=https://www.supermotors.net/registry/media/839906][img]https://www.supermotors.net/getfile/839906/thumbnail/fuseblocksrelays.jpg[/img][/url]
The SPST dash switches carry NONE of the accessories' loads, so they can all be very-low-current (inexpensive) switches. All the accessory load goes through the relays at the far Right of the diagram.
"Low-draw" means any accessory supplied with a 5A fuse or smaller. The total load on either control relay should not exceed ~25A.
"High-draw" means any accessory with a peak draw of 5~40A (60~500W). For 25-40A loads, be sure to use a 40A relay.
"Internal switch" means any primary control switch included with, attached to, or built into an electrical accessory, including a thermocouple chiller/cooler's external selector switch.
"RD" means radar detector. It's grouped with "engine-on" accessories because it's not needed if the vehicle is parked. The stereo & CB could be used while parked, so they're "key-on" accessories.
"Winch control" means a hard-wired dash switch to control a medium or large electric winch's built-in relays, or electric solenoid valves for a hydraulic winch. It does NOT mean the high-current inline control switch used on some very-light-duty (ATV) winches. ANY electric winch's main power wire should be connected directly to the starter relay's battery stud. I chose to connect this to the engine-running circuit for several reasons:
1) a winch draws a LOT of current, so the alternator needs to be putting out to help it run, and so the battery isn't drained too low to start the engine later;
2) the engine & drivetrain should always be used to help the winch move the vehicle, and the steering wheel needs to be unlocked (on vehicles with key-steering interlock);
3) when the key is removed, the dash switch is disabled, so someone inside the vehicle without the key can't easily or accidentally operate it;
4) if the winch is required with the key off, the SPDT control switch can be moved to the battery override position temporarily.
Those are all just suggestions based on best practices. This diagram is easily adaptable to almost any safe configuration.
This diagram was created from this set of symbols using MSPaint:
[url=https://www.supermotors.net/registry/media/858661][img]https://www.supermotors.net/getfile/858661/thumbnail/wiringsymbols.gif[/img][/url]](https://www.supermotors.net/getfile/1076611/fullsize/auxfuserelayeb.jpg)