What Index Sensors & Controls makes

Index Sensors & Controls is a manufacturer of switches, sensors, and controls for the commercial truck, engine, agricultural, off-road, and industrial equipment markets. Its products monitor, control, and protect heavy equipment, and the company frames its role as working "behind the scenes" to improve machine operation, diagnostics, and maintenance costs. Manufacturing and headquarters are in Arlington, Washington.

The catalog spans two families. The switch line runs from mechanical bi-metal temperature switches, the company's founding technology, through electronic temperature switches and heavy-duty pressure switches. The sensor line covers temperature, pressure, liquid level, position, and ABS sensors, along with level probes. Temperature sensors offer single or dual outputs, analog or PWM signals, and SAE J1939 CAN Bus communication, and the company states they are tested to IATF standards at its facility. Rounding out the range are CAN control modules, A/C protection systems, fan-timing controls, and custom harnessing. Index supplies both standard configurations and custom-engineered products, selling to OEMs directly and through independent heavy-duty parts distributors worldwide.

A distinguishing thread is A/C protection. In the early 1990s Index built the K7 Fan Control Kit to stop A/C-triggered cooling fans from cycling too fast and wearing out fan clutches; the company says A/C-triggered fan timing was later built into the engine control modules introduced in 1994. In 1995 it introduced APAds, an air-conditioning protection and diagnostic system that suspends A/C operation under harmful pressure or voltage conditions and returns diagnostic fault codes. The company reports a 9-million-mile field test on more than 100 trucks in which A/C maintenance costs ran up to 64% lower with APAds installed, and states that more than 500,000 APAds systems have been fitted on North American trucks. A simpler AC-X10 Life Extender followed in 2002.

Ownership and history

The company was founded in 1976 as Index Industries when Richard Englund, an engineer experienced in bi-metal thermal switches, bought and revived a switch product line that had sat dormant for seven years. Englund pointed the technology at engine and vehicle applications after finding a need for more precise on-off control of fan clutches in Class 8 trucks, and developed a vibration-resistant "double-snap" switch design that remains the core of the line. The company added engine-mounted electronic temperature switches in the early 1980s and pressure switches in the late 1980s, extending the same double-snap principle into air conditioning, transmission, oil, and air pressure applications.

Index Sensors & Controls is privately held and independent, with no parent company or acquisition on record. It operates a single two-story manufacturing facility and headquarters at 17212 51st Ave NE in Arlington, Washington. Public directories place the workforce in an 11 to 50 band; the company does not publish headcount or revenue figures. This profile does not name current executives because the company does not publish a leadership page and the one widely listed name is out of date.

Certifications and quality

Index is certified to ISO 9001:2015, with a certificate issued by Amtivo (USA) Inc. and dated 2025, posted on the company's own site. An earlier 2024 catalog cited the same certification under Orion Registrar, which Amtivo has since absorbed, so the certification lineage is continuous under a renamed registrar. The company describes quality as a top priority and states that its temperature sensors are tested to IATF standards at its facility. That is a testing claim rather than a claim of IATF 16949 site certification, and it is reported here as the company states it. Index also publishes a Conflict Minerals Position Statement and a Limited Product Warranty.

Known customers

Index names its customers on its own about page, which is unusual for a components supplier and lets these relationships be treated as company-documented rather than inferred.

The company also describes itself as a supplier to "a wide range of specialty original equipment manufacturers" across heavy-duty highway, automotive, construction, agriculture, marine, defense, and industrial applications, and states a growing focus on electric-vehicle sensing and controls. These are company statements about the sectors it serves rather than named accounts.

Sourcing evidence

Index Sensors & Controls appears in US customs records as a light importer, consistent with a domestic manufacturer that builds in Washington and imports selected components rather than finished goods. The public record shows 20 US sea-import shipments, with the most recent dated April 2025. Its named foreign suppliers include Wenzhou Longfar Automobile Parts and Dongguan Hai Qiao Electronics Technology in China, Cangnan Leduo Packing, and Sunonwealth Electric Machine Industry in Taiwan, a supplier mix of automotive parts, electronic components, cooling fans, and packaging that fits a sensor and switch assembler sourcing sub-components abroad. Buyers weighing supplier tiers and tariff exposure should note that a light import footprint is normal for a US-based manufacturer of this size.

Coverage caveats: these are US ocean-freight records only. Air, truck, and rail movements do not appear, some records name freight intermediaries rather than manufacturers, and product categories come from declared manifest codes, which are noisy. Absence of a record is not evidence of absence, and detailed shipment histories behind the summary counts were not purchased for this profile.

Frequently asked questions

What does Index Sensors & Controls make?

Index Sensors & Controls manufactures switches, sensors, and controls for commercial trucks, engines, and off-road and industrial equipment. The range includes mechanical and electronic temperature switches, pressure switches, temperature, pressure, liquid level, position, and ABS sensors, CAN control modules, A/C protection systems, and custom harnessing. It sells standard and custom-engineered products to OEMs and through independent distributors.

Who owns Index Sensors & Controls?

Index Sensors & Controls is a privately held, independent company. It was founded in 1976 as Index Industries by Richard Englund, an engineer who revived a bi-metal thermal switch product line and aimed it at Class 8 truck applications. There is no parent company or acquisition on record.

Who are Index Sensors & Controls' customers?

On its own about page, Index names Cummins, Caterpillar, John Deere, and all makes of Class 8 trucks among the equipment manufacturers it supplies. It also serves specialty OEMs across heavy-duty highway, automotive, construction, agriculture, marine, defense, and industrial markets, and sells through independent heavy-duty parts distributors worldwide.

Where is Index Sensors & Controls located?

Index Sensors & Controls' manufacturing facility and headquarters are at 17212 51st Ave NE, Suite 116, Arlington, Washington 98223. It operates from a single two-story building at that address.

What certifications does Index Sensors & Controls hold?

Index is certified to ISO 9001:2015, with a certificate issued by Amtivo (USA) Inc. dated 2025 and posted on its site. The certification carries over from an earlier registration under Orion Registrar, which Amtivo absorbed. The company also states its temperature sensors are tested to IATF standards at its facility.

How long has Index Sensors & Controls been in business?

Index Sensors & Controls has been in business since 1976, about 50 years. It began as Index Industries with a bi-metal thermal switch line and expanded into electronic switches, pressure switches, sensors, and control modules over the following decades.

Last verified September 27, 2026. Is this your company? Request a correction.