Faria 90406 Dual Station Water Temperature Sender — 1/8" NPTF, American Standard

Faria 90406 — Dual Station Water Temperature Sender, 1/8" NPTF, American Standard

Overview

The Faria 90406 is a dual-station marine water temperature sender that operates two compatible Faria temperature gauges from a single sender location. It uses a 1/8" NPTF threaded connection, a 10-32 stud terminal, and the American / US-ohm resistance standard with a standard-ground configuration. The sender grounds through its threaded body — metal-to-metal contact at the installation port is required for correct operation.

Important: Do not select this sender by thread size alone. A 1/8" sender can physically install and still produce incorrect gauge readings if the resistance standard or station type does not match your gauge system. Confirm that your installation requires an American dual-station temperature sender before ordering.

Key Features

• Dual-station design — drives two compatible temperature gauges simultaneously from one sender
• 1/8" NPT / NPTF thread — installs directly into the engine temperature port or an approved adapter
• American / US-ohm resistance standard — must match gauge system specification
• Standard-ground configuration — grounds through threaded body to the engine block
• 10-32 stud terminal for gauge wiring connection
• OEM cross-reference: factory PN TS1056

Compatible Applications

• Marine installations with two helm stations or two temperature gauges monitoring the same engine
• Faria dual-station temperature gauge systems using the American / US-ohm resistance standard
• Replacement sender for any gauge system originally equipped with a 1/8" NPTF, American dual-station temperature sender
• Compatible with engines having a 1/8" NPT temperature sender port — a bushing or adapter can be used for larger ports without affecting sensing accuracy
• Always confirm that the gauge system requires an American dual-station sender before ordering — resistance standard and station type must match the gauge

When to Replace

• One or both temperature gauges reading erratically, pegged at maximum, or not responding
• Sender terminal is corroded, damaged, or has lost continuity
• Diagnostic testing confirms the sender is not providing the correct resistance signal
• Replacing a mismatched sender that was causing inaccurate temperature readings

Installation Notes

• Install the sender into the engine temperature port or an appropriate adapter — a bushing can be used for larger port sizes without affecting accuracy
• This is a standard-ground sender — the threaded body is the ground path; do not use Teflon tape or thread sealant that electrically insulates the threads, as this will break the ground circuit and cause inaccurate readings
• If the engine also has a separate low-temperature warning switch, a T-fitting may be required to accommodate both devices at the same port
• Connect the gauge lead(s) to the 10-32 stud terminal
• After installation, start the engine and verify both temperature gauges respond correctly through the operating range before returning the vessel to service

Technical FAQ

• What is the difference between a single-station and dual-station sender? A single-station sender is calibrated to drive one gauge; a dual-station sender is calibrated to drive two gauges simultaneously. Using a single-station sender where a dual-station is required (or vice versa) will cause both gauges to read incorrectly, even if the thread fits perfectly.
• What does "American standard" mean? It refers to the US-ohm resistance curve used by the sender. Faria senders are available in American (US-ohm) and European (VDO-ohm) resistance standards. The gauge and sender must use the same resistance standard or readings will be inaccurate.
• Why can’t I use Teflon tape on the threads? Teflon tape is an electrical insulator. This sender uses the threaded body as its ground connection — wrapping the threads in Teflon tape breaks the ground circuit and causes incorrect or no gauge response. Use a compatible non-insulating thread sealant only if sealing is required.
• My gauges read correctly but one reads differently than the other — what should I check? Verify both gauges are the same model/standard and that gauge wiring connections are secure. A resistance difference between gauges may indicate a wiring issue or a gauge calibration difference rather than a sender problem.
• Can this sender be used with non-Faria gauges? Yes, provided the non-Faria gauge uses the American / US-ohm resistance standard and is designed for a dual-station sender. Confirm the gauge manufacturer’s sender specification before substituting.

Part Numbers & Cross-References

• Faria part number: 90406
• Factory reference: TS1056
• SKU: 678-90406
• UPC: 759266904064

Parts Desk Insights

Best Use Case: This sender is the right choice for a boat with two helms or two temperature gauges reading the same engine, where the original dual-station sender has failed or been replaced with an incorrect single-station unit. A single-station sender may look nearly identical and use the same thread, but its resistance characteristics are different and will cause both gauges to read incorrectly. Getting the dual-station, US-ohm sender right is what keeps both gauges accurate.

Common Issues: The most frequent problem is customers ordering a 1/8" temperature sender by thread size alone without verifying the resistance standard or station type. If both gauges read incorrectly after a sender replacement, the first thing to check is whether the correct resistance standard and station type were installed. The second common issue is a broken ground path from thread sealant — remind customers not to use Teflon tape on the threads of a standard-ground sender.

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