Skip to content
Celebrating over 50 years of Trusted Marine Service
Over 50 years of Trusted Marine Service

Sierra Power Trim Relay – Mercury & MerCruiser | 47-5729

Original price $43.69 - Original price $43.69
Original price
$43.69
$43.69 - $43.69
Current price $43.69
Item locally warehoused

Free returns on all eligible orders

You have 30 days to request a return. All sale items are final sale.

Sierra Power Trim Relay – Mercury & MerCruiser | 47-5729

Restore full power trim and tilt function to your Mercury outboard or MerCruiser sterndrive with this Sierra replacement power trim relay. This 12V relay controls the direction of the trim/tilt motor — allowing the engine or drive to tilt up and down on command. When the relay fails, the trim system typically stops responding in one or both directions, making it one of the first and most cost-effective components to check before replacing the trim motor itself.

Compatible Applications

  • Mercury outboard engines with power trim/tilt systems
  • MerCruiser sterndrive applications with power trim systems
  • Replaces Mercury OEM: 87-859217A1
  • Refer to Sierra’s current application guide to confirm fitment for your specific engine model and year

Key Features

  • 12V relay controls trim motor up/down direction
  • Built to OEM specifications for reliable switching performance
  • Direct-fit replacement design
  • Compact and lightweight for easy access installation

Parts Desk Insights

When a Mercury or MerCruiser power trim stops working in one direction — or stops entirely — the trim relay is the most common culprit and the lowest-cost fix to try first. Before replacing the trim motor, swap the relay and test. It’s a straightforward diagnosis: if the trim works after replacing the relay, you’re done. If not, the trim motor or pump is the next step. For the Johnson/Evinrude equivalent, see the Sierra Power Trim Relay for Johnson / Evinrude (47-5705). If you’ve confirmed the relay is good and need the trim motor itself, see the ARCO Heavy-Duty Tilt/Trim Motor for OMC Outboards or browse our full range of tilt/trim motors for your application.

Shipping information

In-stock and OEM parts: ship same or next business day.

Locally warehoused items: ship within 1-3 business days.

Special-order items: timeline confirmed after order.

Returns & warranty

Returns & Satisfaction Guarantee

We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.

If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.

To qualify for a return:


  • Item must be in new, unused condition

  • Product must be in its original packaging

  • All parts, components, hardware, manuals, and accessories must be included

  • Packaging must be undamaged and suitable for resale

Important:

Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.

We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.

For return authorization, please contact our support team before shipping anything back.

Free Shipping

When you spend $150 or more

Here to Help

Get in touch with us

Store Pickup

Pick up your order yourself, for free

Easy Exchanges

Return or exchange within 30 days