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Alpha One remote controls

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18Warrior

Contributing Member
Help! I just bought my first ever I/O, a Merc 5.7 with an Alpha 1 outdrive. On the remote control there is a 'trailer' button, and a trim up/down rocker switch. Can anyone school me on how to operate these buttons? I'm used to outboards, with a simple trim up/down rocker switch. Right now, the outdrive is in the trailer (fully raised) position. How do I get it down to run the boat???
 
Up/down TRIM button will trim all the way down.

When trimming up with the same button, it should only go up about a count of , 1 one thousand, 2 one thousand, 3 one thousand and STOP.
There is a trim limit switch which should stop it. This is the usable trim up before cavitation occurs if the trim limit switch is adjusted correctly. It is adjustable. It one of the plastic pucs at pivot of outdrive. On passenger side of drive.

The other button is the Trailer button. It will raise drive at any time and that includes when trim limit has occurred when using trim button.

Understand?
 
kghost said:
Up/down TRIM button will trim all the way down.

When trimming up with the same button, it should only go up about a count of , 1 one thousand, 2 one thousand, 3 one thousand and STOP.
There is a trim limit switch which should stop it. This is the usable trim up before cavitation occurs if the trim limit switch is adjusted correctly. It is adjustable. It one of the plastic pucs at pivot of outdrive. On passenger side of drive.

The other button is the Trailer button. It will raise drive at any time and that includes when trim limit has occurred when using trim button.

Understand?
Click to expand...
when using just the down button on the trim, it won't go down! It wants to try and go up, till the pump stalls.
 
how about a little more info.
What year is the boat? Serial number of engine?

They had 5.7 alpha drives gen 1 and gen 2 since early/mid '80's
 
and, once you get this fixed, remember to store the boat with the outdrive DOWN anytime its going to be parked...
 
kghost said:
how about a little more info.
What year is the boat? Serial number of engine?

They had 5.7 alpha drives gen 1 and gen 2 since early/mid '80's
Click to expand...
It's a 1988 Glastron Carlson CV 23. I don't have an engine serial number, but the drive number is shown in the attached picture.
 

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makomark said:
and, once you get this fixed, remember to store the boat with the outdrive DOWN anytime its going to be parked...
Click to expand...
With the trailer it's on, I can only lower the drive so far, about 1/2 way down. I'm going to have to put the trailer on blocks for the winter, so I can drop the drive all the way down.
 
18Warrior said:
With the trailer it's on, I can only lower the drive so far, about 1/2 way down. I'm going to have to put the trailer on blocks for the winter, so I can drop the drive all the way down.
Click to expand...
If you look at the rounded area just ahead of the studs & nuts where the drive is attached, you'll see two round parts where the drive pivots when the trim switch is used. One is the limit switch, one is for the trim gauge. The limit switch (port side) needs to be adjusted (screws loosened and the round part rotated clockwise, to allow the drive to trim down farther. It will also need to be adjusted to prevent the drive going up too far. The drive needs its upward limit to prevent damaging the U-joints while the boat is under way and while trim down isn't limited, trim up limit should make it stop at about 15° above vertical with the boat on a level surface. I don't remember the exact number, but the measurement on the trim cylinder should be roughly 21-3/4" between the center of each nut (will verify this later- my manual is in my garage).

The square button allows raising the drive much higher, to prevent dragging it on the launch ramp or road.
 
jimn said:
If you look at the rounded area just ahead of the studs & nuts where the drive is attached, you'll see two round parts where the drive pivots when the trim switch is used. One is the limit switch, one is for the trim gauge. The limit switch (port side) needs to be adjusted (screws loosened and the round part rotated clockwise, to allow the drive to trim down farther. It will also need to be adjusted to prevent the drive going up too far. The drive needs its upward limit to prevent damaging the U-joints while the boat is under way and while trim down isn't limited, trim up limit should make it stop at about 15° above vertical with the boat on a level surface. I don't remember the exact number, but the measurement on the trim cylinder should be roughly 21-3/4" between the center of each nut (will verify this later- my manual is in my garage).

The square button allows raising the drive much higher, to prevent dragging it on the launch ramp or road.
Click to expand...
Read my first reply. No need to repeat info already posted!!!!!

Also if I read your post correctly it is so wrong...

Trim limit is ONLY to set usable range when trimming up so not to induce cavitation or prop blow out....

It has ZERO affect on upper trim limit when the trailer button is used. Nor does it limit full trim up in order to minimize ujoint anything. The upper limit is engineered into the mechanical limits of trim rams.
 
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18Warrior said:
when using just the down button on the trim, it won't go down! It wants to try and go up, till the pump stalls.
Click to expand...
Ok you have posted conflicting information. Above you said it wont go down and then in another post you say it goes down 1/2 way do to low trailer.

Which is it???
Try not to do this. If you are referring to what happened when it would go down say so.
So which is it? It will not go down at all or it will only go down 1/2 way ??????
 
It was 1/2 way down when I bought it, the skeg almost on the pavement. The seller raised it up for towing. Now I can't get it to go down.
 
jimn said:
I think measuring the amount of trim on the cylinder is a bit more accurate than counting to three- how fast should they count?
Click to expand...
Again you are so wrong. Too many contributing factors for a specific dimention. Experience would prove this.

Besides, I was using a easy to follow "this is what should happen while pressing the trim up button"
 
18Warrior said:
It was 1/2 way down when I bought it, the skeg almost on the pavement. The seller raised it up for towing. Now I can't get it to go down.
Click to expand...
Go to trim pump.
Two hydrualuc lines.
Losen both so a little fluid leaks out and then retighten. Now retry the down trim button.

When trimming up or down to limit you will hear a tone change in trim pump.
STOP when you hear this so not to over pressurize the valving in pump.

When using trailer button to raise drive all the way up, once tone change is heard, release button and then immediately press trim down for a second to relieve pressure on the up valve in trim pump to avoid over perssurizing it!
 
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In post #8, jimn is incorrect about down trim. There is no down adjustment. Unit goes down until cylinders fully retrack, PERIOD.
However, he is correct that it limits upward trim to 21 3/4" nut to nut. This dimension is approx 21 degrees of travel from full down.

The real purpose of the trim limit isnt about cavitation (each boat will be different) but to keep the lower sides of the bellhousing inside the side supports of the gimbal ring so things don't break off in a large rotating mass.

You have the 2 wire pump. The pump reverses rotation because the 2 relays in unison reverse the positive & negative within the relays. In reality, both green & blue pump motor leads are connected to ground simultaneously thru the relays when you are NOT pressing any control buttons. Operating either up or down operates 1 relay only (the correct respective relay) to connect that pump lead to positive. Blue = sky, Green = grass. That is which wire becomes positive when you operate either button.

I do agree, your post is a bit confusing. Let's clarify a bit...

1) You recently bought a boat with the drive too low to trail home. Seller pushed the "Trailer button" & unit went up. You drove safely away? YES/NO?

2) Now you are home & unit won't go down using the DOWN side of the trim rocker switch? YES/NO?

3) Are you saying pressing the down side of the trim rocker switch causes drive to want to go up or does nothing?

4) Do you understand that the "Trailer button" is for UP only & will not cause down operation? YES/NO Do not press trailer & down trim rocker switches simultaneously!

5) Are you saying as the boat sits on the trailer there is insufficient clearance to put the drive down assuming the system works but at this time you can NOT get the pump to run in the down direction? YES/NO

6) You understand you DO NOT press the Down side of the rocker switch and "trailer button" simultaneously? YES/NO

Again for clarity:
Trim limit is 21 degrees travel from full down. It is adjusted with the trim limit switch located on the gimbal. Unit should stop at 21 3/4" measured center to center of trim cylinder mounting studs.

"Trim UP" rocker switch will raise unit from full down to the trim limit & stop.
Further UP trim (actually the TILT range of travel, designed for slow speed operation) is obtained by using the "trailer button". The "trailer button" will actually operate the drive UP anywhere in its range of travel from full down to full up. So in the event of a failure of the Trim limit switch or wires, the drive can be raised.

The "Trim Down" rocker switch will operate the drive DOWN anywhere in its range of travel from full up to full down. It does NOT have anything to do with trim limit.

Mercruiser placed these switches so your thumb can operate trim while controlling throttle. TILT up beyond the limit requires you to move your hand down the control handle. Do not operate rocker switch & trailer buttoms simultaneously (which would require both hands)!
 
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Droid said:
In post #8, jimn is incorrect about down trim. There is no down adjustment. Unit goes down until cylinders fully retrack, PERIOD.
However, he is correct that it limits upward trim to 21 3/4" nut to nut. This dimension is approx 21 degrees of travel from full down.

The real purpose of the trim limit isnt about cavitation (each boat will be different) but to keep the lower sides of the bellhousing inside the side supports of the gimbal ring so things don't break off in a large rotating mass.

You have the 2 wire pump. The pump reverses rotation because the 2 relays in unison reverse the positive & negative within the relays. In reality, both green & blue pump motor leads are connected to ground simultaneously thru the relays when you are not pressing any control buttons. Operating either up or down operates 1 relay only (the correct respective relay) to connect that pump lead to positive. Blue = sky, Green = grass. That is which wire becomes positive when you operate either button.

I do agree, your post is a bit confusing. Let's clarify a bit...

1) You recently bought a boat with the drive too low to trail home. Seller pushed the "trailer button" & unit went up. You drove safely away? YES/NO?

2) Now you are home & unit won't go down using the down side of the trim rocker switch) YES/NO?

3) Are you saying pressing the down side of the trim rocker switch causes drive to want to go up or does nothing?

4) Do you understand that the "Trailer button" is for UP only & will not cause down operation? YES/NO Do not press trailer & down trim rocker switches simultaneously!

Again for clarity:
Trim limit is 21 degrees travel from full down. It is adjusted with the trim limit switch located on the gimbal. Unit should stop at 21 3/4" measured center to center of trim cylinder mounting studs.

"Trim UP" rocker switch will raise unit from full down to the trim limit & stop.
Further UP trim (actually the TILT range of travel, designed for slow speed operation) is obtained by using the "trailer button". The "trailer button" will actually operate the drive UP anywhere in its range of travel from full down to full up. So in the event of a failure of the Trim limit switch or wires, the drive can be raised.

The "Trim Down" rocker switch will operate the drive DOWN anywhere in its range of travel from full up to full down. It does NOT have anyt
Click to expand...
with regards to your statement above regarding trim limit is NOT for cavitation is incorrect. That is exactly what it is used for. That is what I was trained to understand at Mercruiser training.

Incase you are not aware, his trim pump is the current generation with the plastic resevoir. It uses TWO Solenoids not relays.

If everyone continues to repeat and slightly redescribe the functions of the buttons/switches it will cause more confusion vs demonstrating your understanding of their function.

Its not rocket science on the simple function of the trim and trailer buttons/switches and I believe the term tilt had been substituted long ago with trailer.
 
FYI....

The primary purpose of the trim limit switch on a MerCruiser outdrive is to act as a safety device, preventing the outdrive from trimming too far out of the water at high speeds. This helps to maintain safe control of the vessel, prevents potential damage to the outdrive unit and trim cylinder from loss of support, and stops the boat from "porpoising" (uncontrolled bow pitching) that can occur from over-trimming. """

The take away from this in less technical terms is, Adjust so Cavitation and or proppeller blow out (leads to over reving of engine) does not occur. Also to maintaine safe operation.
 
Kghost

I stand corrected. It is the 3 wire pump.
The switches still operate the respective solenoid but ground if thru the common black wire.

Yes, the term tilt was eliminated a long time ago but I used it to differentiate between trim range of 21 degrees and the upper range used for low speed shallow water & trailering operations.

Regarding the purpose of the trim limit switch, see the attached picture, right hand column "caution" taken from MerCruiser manual 90-12934R2 which covers R/MR & Alpha Gen1.
 

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kghost said:
Again you are so wrong. Too many contributing factors for a specific dimention. Experience would prove this.

Besides, I was using a easy to follow "this is what should happen while pressing the trim up button"
Click to expand...

Thought I would add this.
 

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18Warrior said:
Just push the 'trailer' button alone, it will drop from the full up tilt position.
Click to expand...
It goes down when you press the square button? It's supposed to go up from the point where it stops going up when using the toggle switch on the handle.
 
jimn said:
It goes down when you press the square button? It's supposed to go up from the point where it stops going up when using the toggle switch on the handle.
Click to expand...
That in my opinion and the merc instructor, is a starting point. Ultimatley the final adjustment is done based on prop and other factors to not allow cavitation or prop blow out and achieve max RPM/MPH!!
 
OK, I got the boat in the water this morning. There is definitely something wrong with the trim wiring. To lower the motor, I have to use the trailer button. Both the up and down toggle switch raises the outdrive, and it doesn't stop at the trim up position, I can tilt the outdrive right out of the water using either the up or down toggle switch. Plus, my trim gauge doesn't work. I have what looks like a small electrical black cord coming from the outdrive, I'm wondering if that is the trim wiring? It's cut off in the engine bay.
 
the cut wires could be either trim puck (sender or limit)...you can probably test the functionality with a good DVM...

Sounds like the wiring has been hacked and needs to be redone by someone that has a clue...
 
Yes, thise wires (2 wires of 2 conductors each) go to trim limit & trim gauge.
They have nothing to do with your switches operating incorrectly. That is from someone (most likely a DIYer) moving things around at the solenoids or control handle.
 
Thanks guys. I do have a clue, even though I'm new to I/O's. I've always run fast outboard boats.
 

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There is a three wire harness from control box to pump.

Near pump is a small Black three prong connector. After connector there should be a two wire bundle in a small holder. This is where the limit switch and trailer button are configured.

On the pump.
Two solenoids.
Top solenoid is UP and small wire should be blue or blue/white. Large wire on one side should be blue to motor.

Bottom solenoid is Down and small wire is green or green/white.
Large wire is Green going to motor.

If all that check out ok then the miss wire is in the control handle.
Two phillips screws to remove cover. There will be wires and male/female pins encapsulated in a plastic pin holder. Pop open holder and match wire colors. They may be missconnected.
 
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