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Replacing Your Trim Limit and Trim Position Senders

Read More About Procedures to Replace Your Trim Senders

Alpha's and Bravo's have two Trim Senders.

They are mounted on either side of the Gimbal Ring.
One sender is for the Trim Gauge and the other sender is for the Trim Limit.

The Trim Limit Switch is mounted on the port side and the Trim Position Switch is mounted on the starboard side.

The switches are prone to damage from water intrusion. Water enters the switch and ruins the contacts. The wires tend to soften and/or rot with age and water leaks into the switch through the wires.

This is why the new switches are sold with the new wires are already attached at the factory. Always replace the wires when replacing the switches.

Symptoms
The Trim Position Switch operates the Trim Gauge.
When the Trim Position Switch fails, the gauge usually pegs to "full up".

The Trim Limit Switch prevents the driver from 'over-trimming" the outdrive while under way.
It is an important limiting feature which prevents damage to the drive and/or loss of control of the vessel.
Trimming the drive unit up too high while the boat is running can cause serious damage and/or injury.
When this switch fails, the TRIM BUTTON does not work. Only the TRAILER BUTTON will work.

When one switch fails, you will end up replacing both switches. This is because the switches are sold in sets of two. Both the Trim Limit and the Trim Sender switches are sold together as a pair.

Replacing the switches requires removal of the drive and bell housing.
These are the same procedures for replacing the Ujoint Bellows.

Replacing Your Alpha One Bellows
Replacing Your Alpha Gen II Bellows
Replacing Your Bravo Bellows

Trim Sender Units
The trim senders are no longer sold individually.
The Port switch is the Trim Limit Switch. This limits how far up the drive will trim.
The Starboard switch is the Trim Level Sender switch. This sends a signal to the trim gauge.

If one or the other malfunctions, you will need to get the entire Kit.
The Kits comes with both senders. The senders are pre-wired from the factory
with new wires.
Mercruiser did this because bad wires were the leading cause for switch failure.

805320A1 Single Station Sender Kit
805320A03 Single Station Trim Sender Kit $99.92


If you have Dual Stations (for example, a gauge below and a gauge on the bridge),
You will also need to purchase the Dual Station sender from below.
Dual Station Gauge Sender
805130A6 Dual Station Trim Sender Kit $79.25
Purchase Manuals for switch replacement procedures.

You will also need a Hing Pin Tool to remove the bell housing.

Read More About Procedures to Replace Your Trim Senders





Sterndrive-Information
Change your Alpha Gear Lube
Change your Bravo Gear Lube
Why does my drive lube have white streaks?
Why does my drive lube have gray mush?
Replace Your Alpha One Water Pump
Replace your Alpha Gen II Water Pump
Rebuild your Bravo Raw Water Pump

Troubleshoot & Replace your Alpha Shift Cable
Troubleshoot & Replace your Bravo Shift Cable

Replace your Alpha One Bellows & Gimbal Bearing
Replace your Alpha Gen II Bellows & Gimbal bearing
Replace your Bravo Bellows & Gimbal Bearing
Why does my drive "Growl" when I turn?
Water is leaking into my boat from the transom

Replacing your Trim Sender Switches
My Trim doesn't work but my Trailer Switch does
My Trim Gauge is Pegged

Rebuild your Alpha One Upper Driveshaft Housing Assembly
Rebuild your Alpha One Lower Gear Housing Assembly

Check your Engine Alignment
Check for Excessive Steering Play
Troubleshoot an Overheating Problem
Should I remove my thermostat?
Why do I overheat when going fast?
Troubleshoot a No-Crank Condition
Troubleshoot a No-Start Condition
My Engine Backfires and/or Surges and has Lack of Power
What is an Anti-Syphon Valve?
My Engine blows Steam from the Exhaust
Why do I hear a "clakity" sound while at idle?
Exhaust Manifolds...IMPORTANT Information
How do I Winterize my engine?

What is Galvanic Corrosion?
I have a Bravo III Galvanic Corrosion Problem
What is a Mercathode?
All about Zinc Anodes
How do I check my carburetor?
What carburetor do I have? A Rochester or a Mercarb?
I have water in my fuel
My fuel smells like varnish
My fuel is old
My engine has been sitting for several months without being run.

I have a Mercruiser 470, 485, 488, 190, 3.7L Engine
I have coolant dripping from the front of my engine
Can I install a regular Alternator instead of the Stator-Rotor?

Converting an OMC to a Mercruiser


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