Pressure Switches

Pressure Switches: a small trigger that tells your system when to act

A pressure switch is a simple electrical trigger that opens or closes a circuit at a set pressure. Plumb one into a fuel, oil, air or boost line, and it watches that pressure and flips a signal at the threshold you choose. People fit pressure switches to arm an auxiliary fuel pump above a set boost, to run a warning light or shutdown when oil pressure drops, or to control an air compressor and lockers. It is a low-cost part that does one job cleanly, and getting the threshold and thread right is the whole game.

What ThreePiece stocks

This category holds 5 pressure switches from 3 brands: DeatschWerks-branded Hobbs switches make up three of them, with one each from ARB and Radium Engineering. Current pricing runs from $64 to $161 for what is in stock right now - that is a live range, not a locked-in price.

On the adjustable end, the Radium Engineering Adjustable Pressure Switch (20-0236) sits at the top of the range around $161. The DeatschWerks 2psi 1/8th NPT adjustable Hobbs switch (1-3psi range) with pigtail (0.5A) covers the low-pressure adjustable band. For a fixed setpoint, the DeatschWerks 15psi 1/8th NPT Hobbs switch with pigtail is the budget end near $64. The ARB SP Pressure Switch, 1/4 NPT, opens 100 / closes 70 (CO35SP) is the air-system option at 1/4 NPT.

How to choose

Three things decide it: thread size, setpoint, and adjustable versus fixed.

  • Thread: the DeatschWerks Hobbs switches here are 1/8th NPT; the ARB is 1/4 NPT. Match the port you are tapping into or plan an adapter.
  • Fixed setpoint: a 15psi Hobbs switch trips at one pressure. Cheapest, simplest, no dialing in - right when you already know your number.
  • Adjustable: the 2psi DeatschWerks (1-3psi range) and the Radium unit let you tune the trigger point on the bench or car. More money, more flexibility.
  • Pigtail: the DeatschWerks switches ship with a pigtail, which saves you sorting connectors. The 4-HOBBS-2 lists a 0.5A rating - size your wiring and any relay to the load you are switching.

What else you need with it

A pressure switch has to tap into a line, so you will usually need adapters to get from your port thread to the switch thread, and fittings if you are building or splicing plumbing. If the switch is triggering a pump, browse fuel pumps in the same section, and if it is watching oil pressure or a cooling circuit, the oil filters and radiators categories round out those jobs. All of these live under Engine Components.

Fitment help and ordering

These switches are sold by thread and setpoint rather than by vehicle, so confirm your port thread and trigger pressure before ordering. If you are unsure, call fitment help at 813-535-5801 or reach us through our contact page. Every order ships with free shipping, and Affirm and Katapult financing is available at checkout.

Pressure Switches: a small trigger that tells your system when to act

A pressure switch is a simple electrical trigger that opens or closes a circuit at a set pressure. Plumb one into a fuel, oil, air or boost line, and it watches that pressure and flips a signal at the threshold you choose. People fit pressure switches to arm an auxiliary fuel pump above a set boost, to run a warning light or shutdown when oil pressure drops, or to control an air compressor and lockers. It is a low-cost part that does one job cleanly, and getting the threshold and thread right is the whole game.

What ThreePiece stocks

This category holds 5 pressure switches from 3 brands: DeatschWerks-branded Hobbs switches make up three of them, with one each from ARB and Radium Engineering. Current pricing runs from $64 to $161 for what is in stock right now - that is a live range, not a locked-in price.

On the adjustable end, the Radium Engineering Adjustable Pressure Switch (20-0236) sits at the top of the range around $161. The DeatschWerks 2psi 1/8th NPT adjustable Hobbs switch (1-3psi range) with pigtail (0.5A) covers the low-pressure adjustable band. For a fixed setpoint, the DeatschWerks 15psi 1/8th NPT Hobbs switch with pigtail is the budget end near $64. The ARB SP Pressure Switch, 1/4 NPT, opens 100 / closes 70 (CO35SP) is the air-system option at 1/4 NPT.

How to choose

Three things decide it: thread size, setpoint, and adjustable versus fixed.

  • Thread: the DeatschWerks Hobbs switches here are 1/8th NPT; the ARB is 1/4 NPT. Match the port you are tapping into or plan an adapter.
  • Fixed setpoint: a 15psi Hobbs switch trips at one pressure. Cheapest, simplest, no dialing in - right when you already know your number.
  • Adjustable: the 2psi DeatschWerks (1-3psi range) and the Radium unit let you tune the trigger point on the bench or car. More money, more flexibility.
  • Pigtail: the DeatschWerks switches ship with a pigtail, which saves you sorting connectors. The 4-HOBBS-2 lists a 0.5A rating - size your wiring and any relay to the load you are switching.

What else you need with it

A pressure switch has to tap into a line, so you will usually need adapters to get from your port thread to the switch thread, and fittings if you are building or splicing plumbing. If the switch is triggering a pump, browse fuel pumps in the same section, and if it is watching oil pressure or a cooling circuit, the oil filters and radiators categories round out those jobs. All of these live under Engine Components.

Fitment help and ordering

These switches are sold by thread and setpoint rather than by vehicle, so confirm your port thread and trigger pressure before ordering. If you are unsure, call fitment help at 813-535-5801 or reach us through our contact page. Every order ships with free shipping, and Affirm and Katapult financing is available at checkout.