Twin Mercruiser 4.3 drive trim issue.

[nyyankees3511]

Hello all, as im finishing up preparing my boat for the summer ive noticed one issue with my twin drive trims. When I trim down from the throttle assembly both drives go down, but when I trim one drive up it seems like both drives are trimming up at the same time using just one of the switches. Any help would be appreciated. Thanks!

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

Hello all, as im finishing up preparing my boat for the summer ive noticed one issue with my twin drive trims. When I trim down from the throttle assembly both drives go down, but when I trim one drive up it seems like both drives are trimming up at the same time using just one of the switches. Any help would be appreciated. Thanks!

:welcome: to iboats

SOunds like it's probably in the control box. What is one of your stern drive serial number?

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

One of the serial numbers is 0m426049. Its in a 2003 sea ray sundancer 280 if that helps!

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

Does it do the same thing in auto or manual mode?

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

what do you mean? the trailer switch works fine. both drives trim down fine but when I try to trim one up using one of the switches both drives go up.

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

what do you mean? the trailer switch works fine. both drives trim down fine but when I try to trim one up using one of the switches both drives go up.

OK, you don't have auto trim so it's either the control module (unless that's not there also) or a bad switch/connection. Also appears you do have a connection between the two trim pumps and it could be a malfunctioning. First find out if the trim is going up as you suspect or it is just your impression. If it is going up, look up Merc manual 28 at Boatinfo - The library, containing manuals, brochures and other technical documents from the last hundred years! / The manual is for Bravo drives but the wiring diagram will be the same. Pull up page 5C-2 and go through the test.

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

thank you, where would the control module be?

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

thank you, where would the control module be?

That's the issue, I don't know if you have one or not. You probably should have one and it would be in the trim pump location but not sure. Need to look at the manual and see if it leads you to the control module or another area which would lead to a cross connection at a switch or relay. Sorry I cannot be more precise but I'm not able to see what you can

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

I looked real close and hard today and I dont see any control module. It seems like its just the wires going from the switches on the handle to each pump on opposite sides. So this seems to be a weird issue.

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

I looked real close and hard today and I dont see any control module. It seems like its just the wires going from the switches on the handle to each pump on opposite sides. So this seems to be a weird issue.

Without a control module I would guess it's in the trailer up switch or wiring going to it. I take it you have one trailer up button or two? If you have two I don't see how there can be a connection between the two, unless someone added one

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

theres only one trailer up switch.

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

New update. I cut one of the blue wires going to the trailer up switch and now they are both working great. So could the trailer switch be the wrong one for two motors?

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

New update. I cut one of the blue wires going to the trailer up switch and now they are both working great. So could the trailer switch be the wrong one for two motors?

If it worked correctly before and now it doesn't then no. If it worked correctly before then I would guess there is a connection being made in the switch and it needs to be replaced. Now if it never work correctly then we would need to dig a bit more

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

I honestly got the boat at the end of last summer so I cant recall. But I do know on the trailer switch both wires are connected together and plugged in on the switch.

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

I honestly got the boat at the end of last summer so I cant recall. But I do know on the trailer switch both wires are connected together and plugged in on the switch.

OK, then that is the way it has always worked your just now realizing it. To fix it you need either two trailer switches or a different trailer switch wired to do the up together. The blue/wht wire is the up wire and the trailer switch bypasses the limit switch. Without a control box I would recommend adding a second trailer switch and separate the two pumps. Below is how the trim is wired.

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

awesome thanks so much for your help! seems someone replaced the switch before and used the wrong one. now to find the right one!

 

[alldodge]

Re: Twin Mercruiser 4.3 drive trim issue.

Use a Momentary DPST (double pole single throw) switch will work to separate the two. This type of switch can be more difficult to find but not impossible. You could also find a Momentary DPDT (double pole double throw) switch and just don't use the constant ON setting. Most Momentary DPDT switches use a Momentary on/off/ constant on settings. You find them many times for things like bilge pump switches.

Only other issue will be that using one switch will be one drive will make it to the top before the other, just mechanics. So if your OK with that (shouldn't hurt anything) just separate the wires.

 

[nyyankees3511]

Re: Twin Mercruiser 4.3 drive trim issue.

awesome! thanks again!