Oil-Pressure Monitoring

The oil-pressure display measures from 0 to 145 PSI.

Oil pressure is one of the most important readings available because a running engine depends on pressurized oil to protect its bearings, crankshaft, camshafts, valvetrain and turbocharger.

Low readings may indicate:

• Low oil level
• Incorrect oil viscosity
• Worn engine bearings
• Oil-pump problems
• Restricted oil pickup
• Excessive oil temperature
• Internal leakage
• Faulty sender or wiring

Normal oil pressure varies by engine, temperature and RPM. Compare the gauge reading against the vehicle or engine manufacturer’s specifications rather than relying on a universal number.

9–32V Digital Voltmeter

The integrated voltmeter displays electrical-system voltage from 9V to 32V, allowing it to operate in compatible 12V and 24V applications.

Voltage monitoring can help identify:

• Weak batteries
• Alternator or charging-system failure
• Loose electrical connections
• Corroded battery terminals
• Excessive accessory load
• Faulty grounds
• Marine charging problems

The voltmeter displays system voltage at the gauge connection. Voltage measured directly at the battery may differ slightly because of wiring resistance and connection quality.

Automatic Warning Functions

The gauge includes preset warnings for all three monitored systems.

High coolant-temperature warning

The temperature warning activates above 203°F.

This threshold provides an early alert, but it does not automatically mean every engine is overheating at 204°F. Normal operating temperature depends on the engine, cooling-system pressure, thermostat and vehicle load.

Low oil-pressure warning

The oil-pressure warning activates below 11.6 PSI.

Oil pressure can briefly read low during starting, and some engines operate near this range at hot idle. However, a warning that appears while driving or remains active as RPM increases should be treated seriously.

Low-voltage warnings

• 12V system warning: Below 11.5V
• 24V system warning: Below 22V

Low running voltage may indicate charging-system failure, heavy electrical load or poor wiring connections.

When a threshold is reached, the display flashes to attract the operator’s attention.

IP67 Water- and Dust-Resistant Construction

The gauge carries an IP67 protection rating, indicating protection against dust and limited water exposure when correctly installed.

Its construction includes:

• 316 stainless-steel bezel
• Scratch-resistant curved glass lens
• Sealed gauge housing
• Lightweight plastic body

The IP67 rating should not be interpreted as permission to pressure-wash the wiring connectors or permanently submerge the gauge. Marine electronics enjoy water considerably less than marine marketing departments imply.

Compact 2-Inch 52mm Design

The gauge measures approximately 2 inches, or 52mm, making it suitable for many universal dashboard openings and mounting panels.

Its single-gauge configuration is useful for:

• Boats with limited helm space
• Compact dashboards
• Off-road vehicles
• Trucks and utility vehicles
• Custom instrument panels
• Engine swaps
• Generator and industrial-engine panels

Verify the required mounting opening and rear clearance before installation.

Compatible With 12V and 24V Systems

The 9–32V operating range supports many compatible:

• Passenger cars
• Pickup trucks
• Heavy-duty trucks
• RVs
• Off-road vehicles
• Boats
• Marine engines
• Industrial equipment

The gauge automatically provides the appropriate low-voltage warning for a 12V or 24V system.

Product Specifications

• Brand: MH
• Manufacturer part number: Mh-Cx6187B+Sensor
• Gauge type: Three-function digital gauge
• Gauge diameter: 2 inches / approximately 52mm
• Water-temperature range: 104–248°F
• Oil-pressure range: 0–145 PSI
• Voltmeter range: 9–32V
• System compatibility: 12V and 24V DC
• Water-temperature warning: Above 203°F
• Oil-pressure warning: Below 11.6 PSI
• 12V low-voltage warning: Below 11.5V
• 24V low-voltage warning: Below 22V
• Water-temperature sender thread: 1/8-inch NPT
• Water sender resistance: Approximately 310–22 ohms
• Oil-pressure sender thread: 1/8-inch NPT
• Oil-pressure sender range: 0–145 PSI
• Oil sender resistance: Approximately 10–184 ohms
• Bezel material: 316 stainless steel
• Lens material: Curved glass
• Housing material: Plastic
• Environmental rating: IP67
• Color: Black

The missing alarm thresholds in the supplied description were verified against matching current product specifications.

What’s Included

• One MH 3-in-1 multifunction gauge
• One 1/8-inch NPT water-temperature sender
• One 1/8-inch NPT oil-pressure sender
• One multi-plug wiring socket
• One instruction manual

Additional thread adapters, wiring, fuse protection or mounting hardware may be required depending on the installation.

Sender Compatibility Matters

The included senders are electrically matched to the gauge:

• Water-temperature sender: 310–22 ohms
• Oil-pressure sender: 10–184 ohms

Do not substitute factory or aftermarket senders unless their resistance curves match the gauge specifications. A sender can physically fit while producing completely inaccurate readings, because apparently matching threads were considered enough cooperation for one day.

Installation Notes

Water-temperature sender

Install the temperature sender in a compatible coolant passage where it remains in contact with circulating coolant.

Possible locations include:

• Cylinder head
• Intake manifold
• Thermostat housing
• Coolant outlet
• Engine block
• Inline radiator-hose adapter

Oil-pressure sender

Install the pressure sender in a pressurized engine-oil passage. Common locations include:

• Factory oil-pressure sender port
• Oil-filter housing
• Oil-gallery port
• Remote sender manifold

The larger oil-pressure sender should not be allowed to hang unsupported from a small engine fitting in a high-vibration application. A remote sender hose or support bracket may be advisable.

Electrical installation

• Disconnect battery power before wiring.
• Confirm whether the vehicle uses a 12V or 24V system.
• Install appropriate fuse protection.
• Use clean power and ground connections.
• Route wiring away from exhaust components.
• Keep wiring clear of belts, pulleys and cooling fans.
• Protect engine-bay connectors from water and corrosion.
• Verify sender wires before applying power.
• Test every function before operating the vehicle.

After installing the coolant sender, bleed trapped air from the cooling system and inspect the connection for leaks. After installing the oil-pressure sender, start the engine and immediately inspect the fitting for oil leakage.

Frequently Asked Questions

What does this triple gauge monitor?

It displays engine coolant temperature, oil pressure and electrical-system voltage from one 52mm instrument.

What are the measurement ranges?

• Water temperature: 104–248°F
• Oil pressure: 0–145 PSI
• Voltage: 9–32V

Does it work with 24V vehicles?

Yes. The listed operating range is 9–32V, supporting compatible 12V and 24V DC systems.

What are the warning thresholds?

• Water temperature above 203°F
• Oil pressure below 11.6 PSI
• 12V system voltage below 11.5V
• 24V system voltage below 22V

Is 203°F always overheating?

No. Many pressurized cooling systems normally operate near or above 203°F. Treat the warning as an alert to monitor the reading and compare it against the engine manufacturer’s normal range.

Is oil pressure below 11.6 PSI always dangerous?

It depends on the engine and operating condition. Some engines may approach that pressure at hot idle, but low pressure while driving or at increased RPM requires immediate attention.

Can I use the factory senders?

Only if their resistance ranges match the gauge. The safer option is to use the included senders.

Are thread adapters included?

The package includes 1/8-inch NPT senders, but additional adapters are not specified. Verify both sender-port threads before installation.

Is the gauge waterproof?

It carries an IP67 rating when correctly installed. Protect the rear connections and wiring from direct water exposure, corrosion and prolonged submersion.

Can the gauge prevent engine damage?

No gauge can guarantee that. It supplies readings and warnings so the operator can respond before conditions become more serious.

What should I do if the oil-pressure alarm appears?

Reduce engine load and stop safely. Shut the engine off if the warning persists or the gauge shows little to no pressure. Check the oil level only after the vehicle is safely stopped.

What should I do if the temperature alarm appears?

Watch whether the temperature stabilizes. If it continues rising, coolant escapes or steam appears, stop safely and shut down the engine. Never open a hot cooling system.

Our guide on how to deal with an overheating engine provides additional diagnostic steps.

Three Critical Readings Without Three Separate Gauges

The MH Triple Gauge combines water temperature, oil pressure and system voltage into one compact 52mm display.

With included senders, 12V/24V compatibility, preset warnings and an IP67-rated housing, it offers a space-saving monitoring solution for compatible cars, trucks, boats, RVs and custom equipment.