2-1/16" CAN-Bus Water Temperature Gauge | 120-260F with Warning | Holley EFI

SKU: FHO2-WT1-HLY
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$177.28 USD
Reads coolant temperature data directly from the Holley EFI ECU through the CAN network. Eliminates the need for an external sender when supported, helping keep wiring clean and installation simple. Precision stepper motor delivers smooth, accurate readings with programmable warning functions and an integrated warning light for added awareness.
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Order leaves our facility in about 2 Weeks
⚠️ Required: Holley EFI Gauge Module (Part 554-130) is required to connect the gauge to the ECU (View on Holley.com).

Holley EFI Water Temp Gauge reads coolant temperature directly from the Holley EFI ECU through the CAN network for a cleaner install with no external sender required when supported. Built for seamless integration with supported Holley EFI systems, it delivers real-time water temperature data while keeping wiring simple and the setup clean. A precision stepper motor keeps the pointer smooth, stable, and easy to read at a glance, while programmable high and low temperature warnings and a settable warning light provide a clear visual alert when coolant temp moves out of range. Daisy-chain capability makes it easy to add multiple gauges on the same CAN network. Built for long-term reliability, it’s made in the USA and backed for life.

Track-Tested. USA-Built. Backed for Life.

Key Features:

  • Direct ECU Water Temp Data — reads coolant temperature directly from the Holley EFI ECU through the CAN network
  • No External Sender Required — eliminates added coolant temperature sender wiring when supported
  • Holley EFI Compatibility — built for seamless use with supported Holley EFI systems
  • Daisy-Chain Capable — supports clean multi-gauge installations on the same CAN network
  • Programmable High/Low Warnings — clear visual alerts when coolant temperature moves out of range
  • Settable Warning Light — user-configurable visual warning for out-of-range coolant temperature
  • Microprocessor-Driven — real-time accuracy
  • Stepper Motor Precision — smooth, accurate pointer movement
  • Made in the USA — backed by a lifetime warranty
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Built to last. Backed for life.
  • Lifetime warranty on internal circuit board electronics
  • 5-year coverage on sensors and wiring
  • Applies to gauges purchased since Jan. 1, 2006

Every Speedhut gauge includes a lifetime warranty* on the electronic circuit board inside the gauge case. It is the core of the gauge — the part responsible for the precision communication that delivers the accuracy and performance Speedhut is known for.

Sensors, wiring, and other external components are covered by an unlimited 5-year warranty.

This combined lifetime / 5-year warranty applies to the original purchaser.
*For your lifetime — as long as you own the gauge — we stand behind it.
Speedhut Inc warrants products to be free from defects in materials or workmanship. This warranty is limited to repair or replacement. Speedhut Inc is not responsible for incidental or consequential damages. Improper use, installation, or unauthorized modifications void this warranty.

If the threads are wrong, you will need an adapter that changes your port to 1/8" NPT. We have some available, ensure you verify it is the right one.

If the sensor fits the threads but is too long, you can try trimming it up to but NOT past the notch. Trimming past the notch will damage the sensor. If it still does not fit, you can get a radiator hose adapter with a 1/8" NPT port.

If you have just installed the gauge, ensure you are using the sensor provided as other sensors will not work. 

If the gauge does not sweep on startup, it is not getting power. Verify the red, white, black power harness is connected properly.

If it sweeps but is not reading at all, ensure the signal harness is connected and pressed in firmly on both sides.

If it's still not working, test the signal harness for continuity with a multimeter. If you have both probes on the metal terminal and it reads "OL" or 0 ohms, the harness is bad.  Call or email us to get a replacement harness. You can put paperclips in the harness connector if needed to get a good contact point.

If the harness is testing good, the next step is to measure ohms coming from the sensor while it is warm. Refer to the chart below, if the ohm reading is close to 0 or it's an OL, you need a new sensor. We recommend reading the ohms at the gauge side to verify it is getting to the gauge.

Temp Sensor Resistance Chart
Temp CTemp FResistance
(Ohms)
60140238
65.55150199
71.11160168
76.66170144
82.22180125
87.77190108
93.3320094
98.8821082
104.4422071
11023061
115.5524051
121.1125043
126.6626036

The sender and gauge must be grounded to the same source to operate correctly.

The sender's ground path is its mounting threads. Ensure that what the sender is threaded into is grounded to the same source as the gauge.

Use Teflon paste on the sender threads to secure the seal and maintain a secure ground connection. Teflon tape will NOT assist the ground connection.

Making a comparison to a Temperature Gun reading should be used as a basic comparison only. A temperature gun only measures surface temperature, and does not measure internal temperature. Surface temperature will always be cooler than the coolant inside the engine. A common temperature difference would be between 5 and 25 degrees, between the water temperature gauge and a temperature gun. This depends on the efficiency of the component being shot with the temperature gun to dissipate heat. So, if your gauge reads 195 and you point & shoot and get a reading of 185, you can safely assume that you are seeing a reasonable, and realistic comparison. Only use a temperature gun to make basic temperature comparisons. Understand, that when everything is working correctly, the gauge will usually read higher since the gauge measures core temperature, and the temperature gun measures surface temperature.

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