Narva Sealed Rocker Switch Off/on Spdt 12V Blue Illuminated Rear Diff Lock Symbol 63138BL

The Narva sealed rocker switch, part number 63138BL, is an Off/On SPDT switch designed for 12V systems and rated at 20A at 12V only. It is supplied as an each item and uses a blue illuminated lamp arrangement with both “Dash light” and “On” illumination.

This switch has a 2-position Off - On action, 5 terminals, and a push fit design with push on terminals. The mounting opening is 37.5 x 21mm, with a stated mount length of 37.5mm, so panel size needs to be checked before fitting.

Narva describes the switch as having a rear diff lock symbol, making the face marking relevant when the control layout needs to be easy to identify. It is a rocker type switch with a sealed construction and a one year warranty.

Key Features

• SPDT switch action
• Off - On, 2-position design
• 12V only, 20A rated at 12V
• Blue illuminated with “Dash light” and “On” illumination
• 5 terminals with push fit design and push on terminals
• Rear diff lock symbol on switch face

Specifications

• Brand: Narva
• Part No.: 63138BL
• Product type: Switch
• Switch type: Rocker
• Voltage: 12V
• Power rating: 20A
• Number of positions: 2
• Switch action: Off - On

Application and Buying Notes

Before ordering, check that your panel has a mounting opening of 37.5 x 21mm and that the switch location can accept a rocker with a 37.5mm mount length. That physical opening is one of the main checks for this part, because the switch is not a universal size-for-size match for every dash or switch panel.

The electrical rating is 20A at 12V only, so it should be matched to the circuit design rather than assumed suitable for heavier loads. The switch has 5 terminals and an SPDT arrangement, so the wiring setup needs to suit the circuit you are building or replacing.

The blue illumination and the separate “Dash light” and “On” lighting are useful if you want the switch to be visible in low light. As with any illuminated switch, confirm that your wiring plan allows for the lamp function as intended and that the system voltage remains 12V.

The rear diff lock symbol is part of the switch face, so it is best suited to applications where that marking matches the function being controlled. If you are replacing an existing switch, compare the part number 63138BL, the action type, terminal count, and panel opening before purchase.

Because the switch is listed as sealed and supplied with push on terminals, it is still worth checking terminal style and clearance behind the panel. Limited space behind the dash can affect how the terminals and wiring sit once the switch is installed.

Before supply, the safest approach is to confirm the original unit details against the listed part number, voltage, output rating, mounting arrangement, and pulley configuration. That checking process is standard practice in the parts trade because visually similar units can still differ in service-critical ways.

For workshop, fleet, and equipment applications, accurate identification of part number 63138BL helps avoid unnecessary freight, additional labour, and vehicle or machine downtime. Where the application is not straightforward, the original unit, OEM reference, or workshop records should be used as the primary confirmation point.

Relevant published details for this unit include Type SWITCH, Unit of Measure EACH, Warranty One Year, Power Rating (Amp) 20, Voltage 12, Mount Length 37.5mm, Number of Positions 2, Switch Illumination Illuminated, Product Group 2 FUSES BREAKERS RELAYS SWITCHES.

Additional published details for cross-checking include Part No. 63138BL, Brand NARVA, Description Narva Sealed Rocker Switch Off/On SPDT 12V Blue Illuminated Rear Diff Lock Symbol (Contacts Rated 20A @ 12V), Number of Terminals 5, Switch Action Off - On, Lamp Colour/s Blue, Number of Poles 1, Switch Type Rocker, Weight 0.04kg, Product Group 1 AUTO ELEC ACCESSORIES.

Narva Sealed Rocker Switch Off/On SPDT 12V Blue Illuminated Rear Diff Lock Symbol (Contacts Rated 20A @ 12V). Part number 63138BL should be checked first. Listed voltage is 12. Listed output rating is 20. These details form the core reference points used by parts interpreters when confirming the correct replacement.

For part number 63138BL, the normal identification sequence is part number, electrical rating, mounting arrangement, connector or terminal style, and pulley or drive details. Using those checkpoints helps confirm that the listed unit matches the service requirement rather than only looking similar.

For a switch in workshop, fleet, trade, agricultural, or construction service, the listed voltage 12 and output 20 should be checked carefully. Incorrect selection can affect installation time, return freight, and equipment availability.

Compatibility note: Confirm fitment by matching part number 63138BL, the 37.5 x 21mm mounting opening, the 12V / 20A rating, and the 5-terminal SPDT Off - On configuration before ordering.

FAQ

What is the part number for this Narva rocker switch?

The part number is 63138BL. For this listing, part number 63138BL is the main reference point. Listed voltage is 12. Listed output rating is 20. These details should still be checked against the original unit before ordering.

What voltage is this switch designed for?

It is specified for 12V systems only. For this listing, part number 63138BL is the main reference point. Listed voltage is 12. Listed output rating is 20. These details should still be checked against the original unit before ordering.

What is the current rating?

The switch is rated at 20A at 12V only. For this listing, part number 63138BL is the main reference point. Listed voltage is 12. Listed output rating is 20. These details should still be checked against the original unit before ordering.

How many terminals does it have?

It has 5 terminals. For this listing, part number 63138BL is the main reference point. Listed voltage is 12. Listed output rating is 20. These details should still be checked against the original unit before ordering.

What size opening is required for mounting?

The stated mounting opening is 37.5 x 21mm, with a mount length of 37.5mm. For this listing, part number 63138BL is the main reference point. Listed voltage is 12. Listed output rating is 20. These details should still be checked against the original unit before ordering.

Does it have illumination?

Yes. It is blue illuminated and listed with both “Dash light” and “On” illumination. For this listing, part number 63138BL is the main reference point. Listed voltage is 12. Listed output rating is 20. These details should still be checked against the original unit before ordering.