K4 Switches 22-101 Relay Socket With Pigtail Wires For Hella's 40 Amp Mini Relays

K4 Switches universal relay plug for 4 or 5 prong relays. Typically used with a conventional 20/40 amp relay for:

• Hard start relay to get the amp load off of your ignition switch
• Headlight relay to run a low amp toggle switch with lights that draw up to 40 amps
• Fan relay to take away the amp draw from the ECU or thermostat to your radiator fans
• Fuel pump relay

If you're using this as a headlight relay, to figure out the amount of amps your lights are using, use the total wattage of your lights and divide that by the volts. For instance if your lights are 100w each then 100w ÷ 12v = 8.33a. So if you had four 100w lights using 33.33 amps and your toggle switch is only rated at 10 amp then you could use that 10 amp toggle switch to activate this 40 amp relay and be covered for the 33.33 amps of lights that you're running.

Wiring (Look at the numbers on the relay):

Always stop and look at the relay to note the positions of each number on each blade ! ! For example Hella's black 40 amp relays have their #30 constant power in a different position than the Hella blue fused relays, and this socket will fit either of those relays.


• #86 wire is switched power on. The trigger wire from a toggle switch or thermostat
• #87 wire goes to your lights, starter solenoid, fuel pump, or radiator fans
• #87a wire is normally not used. When the toggle switch is turned OFF to 86 the 87a then becomes ON
• #30 wire is for 12v constant power. Obviously run a fuse or circuit breaker on this wire
• #85 is a ground wire