Alpha 1 Will Not Go Up

[chishol7]

I have an 89 Thompson with a 4.3L Merc Alpha 1 that will not trim up. The boat was being stored with the outdrive all the way down for the winter but I had to move it so I raised the drive, but it only went about half way up. After moving it, I started to play with the trim. . . it goes down normally but each time I try to trim it up it only goes about half as far as it went the previous time.

Everything sounds normal.

Batteries are fully charged.

The fluid level is good but it appears to be ATF (red) so I am not sure if that could be a part of the problem? Whatever the fluid is, it has been there for five years and everything has worked fine up to this point. There are no visible leaks.

I have only used this boat 5 or six times since the fall of 2006, it is stored in a heated barn.

I flip-flopped the wiring to the solenoids and the situation persists.

It looks like you have to pull the outdrive to get to those trim limit switches (at least the one on the port side) so I figured I would look for some advice here before I go any further. Thanks in advance.

 

[tpenfield]

Re: Alpha 1 Will Not Go Up

On the mercruisers there should be a 'trim' button and a 'trailer' button. The trim only takes the drive about half way up. The trailer button has to be used to take the drive all the way up.

You should be able to get at the trim limit and trim position switches without taking the drive off. It may be that the trim limit switch is loose or messed up internally.

Is there a separate 'trailer' switch and does that do anything?

 

[chishol7]

Re: Alpha 1 Will Not Go Up

There is only one tilt/trim control and that is on the throttle. The results that I am talking about are happening while squeezing the tilt and trim together.

I am not sure what the part is called, but what I am assuming is the limit switch on the port side is behind a cast aluminum structure that looks like it would stay with the boat if I pull the drive.

 

[picklenjim]

Re: Alpha 1 Will Not Go Up

Turn the steering to the right!

 

[Scott Danforth]

Re: Alpha 1 Will Not Go Up

its either electrical related to the trim/tilt, or you could have low fluid. if the pump still runs but it wont move, you have low fluid. if it tilts up so far then just stops, look at the tilt/trailer circuit

 

[Harritwo]

Re: Alpha 1 Will Not Go Up

Check on the lower aft corner for a trailer mode in the trim switch. When the limit switch goes out, the one that you are looking at, the trim indicator does not work but the motor will still raise up and down. You just do not know the position of where your drive is, and the switch will not cut the pump out when it hits the stop. Check for a trailer mode switch that.

 

[nikon]

Re: Alpha 1 Will Not Go Up

So we don't have to keep guessing...does the motor stop running half way up? Or does the motor continue to run and the drive stops moving.

 

[chishol7]

Re: Alpha 1 Will Not Go Up

So we don't have to keep guessing...does the motor stop running half way up? Or does the motor continue to run and the drive stops moving.

It keeps running and the tone never changes the way it does when it reaches the top when all is working properly.

 

[Scott Danforth]

Re: Alpha 1 Will Not Go Up

your low on fluid

 

[chishol7]

Re: Alpha 1 Will Not Go Up

your low on fluid

Nope. Fluid level is where it is supposed to be. At the max line with the drive down, well above min with the drive up.

I just spent an hour out in the barn messing with this thing. The bottom wire going to the trim limit switch (port side) is broken off at the point it enters the main body of the switch and appears as if it can not be reconnected. So I twisted the broken wire to an exposed portion of the still attached wire and was able to get the drive to go up, but it is very slow. 60 seconds to go all the way up type slow. I'll try to make a cleaner bypass tomorrow. . .

 

[Don S]

Re: Alpha 1 Will Not Go Up

If the pump is running, you don't have an electrical problem, you have a hydraulic problem. Either one of the trim cylinders is bypassing fluid, or the pump is bad. Getting the system pressure tested is the only way to know for sure where the problem is.
You might disconnect the up line from the pump and plug the pump and listen to see if it sounds like it's full up when it runs. If not, you have pump problems.

 

[nikon]

Re: Alpha 1 Will Not Go Up

Disconnect the rams from the drive, then run the pump up. They should go up at approximately the same rate, if one goes all the way and the other gets stuck it's possible you have a defective ram.

There is also a bypass valve that could have gone bad, only way to know for sure is to get a pressure reading on it though.

Seeing as the pump noise stays the same my bet is on the pump or the bypass valve. If the rams went bad it would start making a lugging sound.

 

[chishol7]

Re: Alpha 1 Will Not Go Up

Disconnect the rams from the drive, then run the pump up. They should go up at approximately the same rate, if one goes all the way and the other gets stuck it's possible you have a defective ram.

There is also a bypass valve that could have gone bad, only way to know for sure is to get a pressure reading on it though.

Seeing as the pump noise stays the same my bet is on the pump or the bypass valve. If the rams went bad it would start making a lugging sound.

First of all I want to thank all you guys for the help.

Looks like I have at least a two part problem. After getting a firm connection with the limit switch bypass (still going up very slowly) I did as Nikon suggested and disconnected the rams. With the rams disconnected they retract at a normal pace but extending them was a different story. Running the trim up for ten seconds moved the starboard ram 1 1/2" and the port side 3/4". Each successive ten second burst moved the starboard side between 1 3/8" and 1 1/2" (yes I used a stopwatch and tape measure), but the port side won't go past the initial 3/4" that it moved during the first ten seconds. The rams retract at a rate of a little more than 1" per second.

I am assuming that I at least need to replace the port side ram but I am wondering if the pump is also bad if the starboard side is only moving at 1 1/2" per ten seconds??? Or is the port side just more deteriorated than the starboard side?

 

[Don S]

Re: Alpha 1 Will Not Go Up

Without pressure testing, you are only guessing. The rams, even when everything is working perfectly will move one at a time. Path of least resistance move first.

 

[chishol7]

Re: Alpha 1 Will Not Go Up

I have no way to pressure test the system where the boat is currently at but would love to get this fixed before I move it north, so I decided to take one last crack at this thing. I flip-flopped the hydraulic lines coming off the pump and the system worked perfectly (backwards, but in and out at a normal pace). I put it back the way it is supposed to be and it still creeps out on the starboard side and barely moves on the port side. I assume that this really narrows down what could be wrong. . . hope one of you guys knows. Thanks.