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Power Trim Sender Kit – Fits MerCruiser MC-I, R, MR, Alpha One, Alpha One Gen II, Bravo (Replaces 805320A03)

Regular price $148.49
Shipping calculated at checkout.

Power Trim Sender Kit – Fits MerCruiser MC-I, R, MR, Alpha One, Alpha One Gen II, Bravo (Replaces 805320A03) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This Power Trim Sender Kit is engineered for a wide range of MerCruiser stern drives, including MC-I, R, MR, Alpha One, Alpha One Gen II, and Bravo models. The kit provides both the trim limit switch and the trim sender switch with wire leads, ensuring your trim gauge and limit functions are restored to factory specifications.

It serves as a direct replacement for Mercury/Quicksilver numbers 805320A03 and 805320A1, as well as Sierra 18-7633 and several other equivalents.

  • Designed for stern drive installations.
  • Features a standard 2-wire connection.
  • Complete kit includes limit and sender switches.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number
Mercury / Quicksilver 805320A03
Mercury / Quicksilver 805320A1
MerCruiser 17693A2
MerCruiser 63115A12
MerCruiser 88678A4
MerCruiser 88678A5
MerCruiser 96863A15
Sierra 18-7633

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Brand Model Years OEM Part No.
MerCruiser MC-I 805320A03
MerCruiser R 805320A03
MerCruiser MR 805320A03
MerCruiser Alpha One 805320A03
MerCruiser Alpha One Gen II 1991 & Newer 805320A03
MerCruiser Bravo 805320A03

Technical Specs

Product Type
Power Trim Sender Kit
Installation
Stern Drive
Connection
2-wire
Housing Color
Black
Package Dimensions
203 x 117 x 122 mm (8 x 4.6 x 4.8 in)
Weight
0.4 kg (0.9 lb)
Other Attributes
Not for use with SmartCraft systems

What’s in the Box

  • 1 x Trim Limit Switch
  • 1 x Trim Sender Switch
  • 2 x Wire Leads

Installation Notes

  1. Disconnect the boat's battery to prevent electrical shorts.
  2. Trim the stern drive to the full "up" or "trailer" position for access.
  3. Locate the old trim sender and limit switch on the gimbal housing.
  4. Carefully disconnect the wire retainers and electrical connectors inside the boat.
  5. Remove the mounting hardware and pull the old switch wires through the transom.
  6. Route the new switch wires through the transom, ensuring a proper seal.
  7. Mount the new sender and limit switches, ensuring they are correctly oriented.
  8. Connect the new wire leads to the engine harness.
  9. Reconnect the battery and test the trim gauge and limit switch functionality.
  10. Apply marine-grade sealant around the wire pass-through to prevent leaks.

Troubleshooting & FAQ

Which MerCruiser drives is this kit compatible with?

This kit is designed for MC-I, R, MR, Alpha One, Alpha One Gen II (1991 and newer), and Bravo stern drives. It is not suitable for models equipped with SmartCraft systems.

What are the signs of a failing trim sender?

Common symptoms include an inaccurate or non-functioning trim gauge, the drive trimming up but not down (or vice-versa), or the trim limit switch failing to stop the drive at its upper limit.

Does this kit include both the sender and the limit switch?

Yes, this is a complete kit that includes the trim position sender, the trim limit switch, and the necessary wire leads for installation.

How do I test my existing trim sender before replacing it?

You can test the sender with a multimeter. Disconnect the sender wires and measure the resistance while moving the drive through its trim range. The resistance should change smoothly. An open circuit, short, or erratic readings indicate a faulty sender.

Is this a plug-and-play installation?

The kit is a direct replacement, but installation requires routing wires through the transom and ensuring proper sealing to prevent leaks. Professional installation is recommended if you are not experienced with stern drive mechanics.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, it is batch-inspected for consistency.

Shipping speed & cost?

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns?

This product is covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window for unused items in their original condition. See our policy page or reach out for instructions.

Safety & Important Info

  • Verify images and specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement part, not an OEM component.
  • Professional installation is recommended for safety and performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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