79-816933A1 Quicksilver Temp Gauge | Genuine Used Part

🔧 Product Description

Genuine Quicksilver QSI Water Temperature Gauge - Part Number: 79-816933A1

A genuine used Quicksilver QSI analog water-temperature gauge with a 100-240°F scale for compatible 12-volt marine temperature-sender systems.

The large QSI instrument monitors engine cooling temperature through a matched resistive sender. Gauge and sender calibration must correspond for a reliable temperature reading.

⚙️ Key Features

• Genuine Quicksilver OEM QSI temperature gauge
• Correct Mercury part number 79-816933A1
• 100-240°F water-temperature scale
• Approximately 3-3/8-inch / 86 mm instrument class
• Illuminated analog display for 12-volt systems

🚤 Compatibility

Commonly used on

• Mercury and Mariner outboard temperature instrumentation
• MerCruiser petrol inboard and sterndrive cooling systems using a matching sender

Typically suits

• Engine models:
• Mercury and Mariner outboards fitted with a compatible resistive water-temperature sender
• MerCruiser petrol sterndrive engines fitted with a compatible 100-240°F sender
• MerCruiser petrol inboard engines fitted with a compatible 100-240°F sender
• 12-volt marine dashboards requiring the larger QSI instrument opening
• HP Range: Not engine-specific; sender and gauge calibration controlled
• Engine Type: Mercury / Mariner outboard and MerCruiser petrol marine engine
• Year Range: Approximately late 1980s - 1990s

🔌 Function

The gauge displays engine cooling temperature by interpreting resistance from the installed temperature sender. It helps the operator identify normal warm-up and abnormal overheating conditions.

⚠️ Common Signs of Failure

• Gauge remains cold after the engine reaches operating temperature
• Needle immediately moves to the hot end of the scale
• Reading fluctuates because of a poor sender ground or loose terminal
• Gauge and sender calibration mismatch produces an inaccurate reading
• Backlighting or internal needle movement fails

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 79-816933A1 current known OEM service reference
• 816933A1 original unprefixed Mercury reference

OEM / Related Numbers

• 79-816933A1
• 79816933A1
• 816933A1
• 745061064126
• Quicksilver QSI 100-240°F temperature gauge

Aftermarket / Verified Equivalents

• Sierra: 62729P - Premier Pro 100-240°F temperature gauge
• Veethree / Teleflex: 84590F - 120-240°F temperature gauge
• Faria: 12812 - Euro Black 100-250°F temperature gauge
• Faria: 13704 - Chesapeake Black 100-250°F temperature gauge

📦 Condition

• Genuine used part
• Removed from running engine where applicable
• In good working condition unless otherwise stated