Blue Sea Systems M-Series Battery Switch Spare Locking Key, Red

Overview

The Blue Sea Systems 7903 is a red spare locking key for compatible M-Series battery switches. It is the replacement key itself, not the switch assembly, so it is used when the original key is lost, damaged, or kept as a backup on board.

This part fits the keyed version of the Blue Sea Systems M-Series battery switch range, including the 6004 Single Circuit ON-OFF with locking key. It gives you back normal access to the switch without replacing the full battery switch body, which matters when the rest of the switch is still in good working order.

On a boat, a missing battery switch key can stop you from isolating a battery bank before storage, service, or electrical work. Keeping a spare like this aboard is a simple way to avoid that problem, especially on small powerboats, tenders, and sailboats using a keyed M-Series switch at the battery compartment or main DC disconnect point.

Key features

• Spare locking key for Blue Sea Systems M-Series battery switches that use a keyed handle
• Compatible with the keyed M-Series setup, including the 6004 Single Circuit ON-OFF battery switch
• Red key matches the red keyed M-Series switch version for straightforward identification
• Useful as a direct replacement for a lost key or as a backup kept on board
• Key-only service part for restoring access without replacing the complete battery switch

Compatibility and fit

This key is for the locking-key version of the M-Series switch, not the standard knob version and not a complete replacement lock set. Before ordering, check that your existing switch is a keyed M-Series model and that you need the spare key rather than the full switch or another service part.

Because this is a mechanical replacement key, it does not change the switch's electrical ratings or the way the battery switch is wired into the boat. Its job is simply to restore operation of a compatible keyed switch that is already installed.

Use on board

This is a sensible spare for owners who lock out battery power when leaving the boat, winterizing, or working on the DC system. It also suits technicians and service crews who want a replacement key on hand so a missing original key does not delay routine electrical work.

Orders are processed within 2 business days, which includes verification, packing, and dispatch. Orders of $100 or more qualify for free shipping when eligible. For orders under $100, shipping costs are calculated at checkout based on destination, package weight, and selected service. International shipping is available for eligible products, and certain items may require additional handling, warehouse transfers, or may ship directly from the manufacturer, which can affect processing time.

Deliveries are handled by preferred carriers such as USPS, UPS, FedEx, DHL, and others depending on your location and selected service. Estimated delivery times are displayed at checkout and may vary due to customs processing, carrier delays, weather, postal disruptions, or other circumstances beyond our control. Once your order ships, you'll receive a confirmation email with tracking information. Tracking may take up to 24 hours to update on the carrier's website and is also available through your account when applicable.

We ship throughout the United States and to most international destinations for products eligible for international shipping. International orders may be subject to customs duties, taxes, brokerage charges, or other import fees, which are the customer's responsibility and are not included in the product or shipping price. PO Boxes are accepted only when shipping through USPS, and not all packages qualify for this option. If your order does not arrive within the estimated delivery window, please contact us at info@apollolighting.com or +1 (954) 375-0100 so we can assist with locating your package.

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Returns may be requested within 30 days of receiving your order. Items must be unused, uninstalled, unaltered, and returned in their original packaging with all tags, packing materials, blank warranty cards, manuals, instructions, accessories, and included items. Certain products, including installed or used electronics, electrical components, lighting, consumables, custom or special-order items, cut-to-length products, safety equipment, and merchandise exposed to water or marine conditions, may not be eligible for return.

To request a return, sign in to your account and select the applicable order and items, and submit your request for review. Eligible unfulfilled items may also be submitted for cancellation within 1 hour of placing the order. Returns or cancellations are not considered approved until you receive confirmation from Apollo Lighting. Please do not ship or drop off merchandise before receiving return approval and instructions.

Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

After your return is received and inspected, approved refunds are issued to the original payment method and may take 5-7 business days to appear after processing. Original shipping and handling charges are nonrefundable, and the value of any included free items that are not returned may be deducted from the refund. Apollo Lighting does not charge a standard restocking fee on eligible returns. Returns that are incomplete, damaged, installed, used, altered, improperly packaged, or otherwise do not meet the eligibility requirements may be refused. We recommend using a trackable and appropriately insured shipping service for all customer-arranged returns.

For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

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Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

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