Help diagnosing 2003 280DA dual throttle trim button issue

[Gunn]

Hello all, I'm having an issue where my starboard trim won't go down at switch but will go down at solenoid when jumped to test according to the Mercruiser manual. So unfortunately the solenoid is good, which means it's either a wiring issue, or more likely an issue with the button on the dual throttle control.

I wasn't able to figure out what model number of Mercury throttle control this is, but it's the stock OEM one on this 2003 280DA.

Has anyone disassembled this thing before and know the wiring schematic? I took off the cover and found a small set of wires, but not sure how they get up the shaft to the handle and switches. I could test them right here and see if I can get the starboard trim down to operate, if I knew which wires to probe or jump...

I also have an issue where the side mounted push button that engages throttle-only control seems to be stuck for the port side. It won't push in. The starboard side works fine. Any ideas on that?

Or maybe it's just time for a new throttle control. Has anyone replaced theirs?!

Thanks,

Tom

 

[Brite Idea]

It's almost never the trim button but it usually is the trim & limit switches. There is a way to test them in the water so do that first.

 

[blaster]

I have the quicksilver single control on my whaler. I had the same issue with the throttle only button stuck in. I was able to pull the button off gently with pliers. I then lubricated and cleaned the controls with a heavy spray of deoxit D5.

https://www.amazon.com/Hosa-D5S-6-DeoxIT-Contact-Cleaner/dp/B00006LVEU

I am not certain about the wiring for the trim switches but the contact cleaner worked great to free everything up without a big oily mess.

 

[ATLTiger97]

Replied to your thread in 280da also. The switches are cheap but you should be able to tell if it the switch from feel. I agree with Brite, it is usually the sender/limit on the drive. I am having those replaces on both since she is getting a full ourdrive service and steering pin replacement.

I dont know why Merc didn’t find an easier was to fish those lines through the drive, seems like they fail first.

Also there is an off brand replacment of the whole console, someone on here did it and said it was a LOT better. However he had to replace the cables as they do not work the original one. I think he said $1k all in.

 

[Gunn]

Thanks everyone, I completely forgot about the limit switch on the outdrive being a possible issue! I actually have the outdrive off and the engine out right now, so a great time to test it. Thanks!

I'll try to use pliers on the button and see what happens, great tip.

This one looks pretty nice: https://www.wholesalemarine.com/ch7800-series-dual-top-mount-control.html . I especially like that the one with tilt and trim has a single button on the left side of the controller that works both at the same time, but also has individual buttons on the console itself. And, what I like even more is that it has arrow buttons to indicate which way the drives move. The one I have now, I can *never* remember if it's a forward push or a rearward pull that makes the drive go up or down! Drives me crazy after all these years. Plus, it does say it works with most all OEM and aftermarket cables...not bad for $492 if that is indeed all that is needed.

 

[Gunn]

Thanks everyone, I completely forgot about the limit switch on the outdrive being a possible issue! I actually have the outdrive off and the engine out right now, so a great time to test it. Thanks!

Ok, haven't been back out to the boat yet, but in thinking more about this I realized that... the trim limit sender is in the trim up circuit only, and will never prevent trim down. And my problem is that the drive "won't go down at the switch". So I don't think it's the trim limit switch in this case.

If I jump the solenoid to test the IN/DOWN solenoid according to the manual (Mercruiser #14 Page 5A-20) by connecting a jumper wire between the positive (+) solenoid terminal and the green-white motor lead terminal, the pump will run and move the drive downward.

So maybe I am back to the switch at the throttle controller?

Tom

 

[Skybolt]

... So maybe I am back to the switch at the throttle controller?
Tom

Hi Tom, Years ago I had a Regal with those trim switches and I actually had to replace one for the opposite, mine wouldn't go up. There is a way to pop out the switches from the handle, but you need to be very gentle with it. I would start there since the other end is working correctly. There is also a Molex connector somewhere by the binnacles that you might be able to jumper out to test the wiring etc. before pulling the switches, but it's probably at the switch itself. The switch itself may still be good, but have a bad connection if not soldered.

 

[Gunn]

Thanks, I'll be sure to check it out!

 

[Gunn]

I finally got out to the boat to do some more diagnosing. I was able to get the trim switches out of the throttle control, but it was difficult. I think that Mercruiser actually glues the bezel in place around the switches so I tried to carefully pry it out and it finally came free. Miraculously, it didn't break. (the switch and bezel are linked to products I found as replacements, just FYI). So here they are:

The red is +12V always.
Purple gets +12V when moving the drive up.
Green gets +12V when moving the drive down.

Unfortunately, my switch is fine. I removed the switch and checked for continuity between the center pin and the outer pins when pressing the switch, and it checked out.

I tried to jumper the +12V to each purple and green wire. Jumping +12V to the purple wire worked fine and the drive moved up. However, nothing happened when I jumped +12V to the green wire. So the green wire power is not getting from the switch down to the trim motor. Since this is in the down position, the trim limit switch shouldn't have any bearing on what is going on in the circuit. So now what!?

I went down to the trim pump and looked around. Coming out of the main assembly is a wire bundle that has blue/white, green/white and red/white wires. The red wire is capped off.

Next, I found where the trim limit switch comes into the harness. The limit switch black wires plug into a purple/white on one wire and two blue/white wires on the other.

Once these two wire harness come together, they then go upward and run into the huge wire bundle running forward along the starboard side. And there are only three wires here: blue/white, purple/white and green/white wires.

These are much heavier gauge wires than appear at the controller switch. And I don't know what the blue/white wire is, as there is no blue wire at the switch. So these may or may not be a 1-to-1 match.

I need to think this over but I'm a bit stumped as to what to check now. I was thinking maybe of trying to figure out how to remove the throttle controller from the base and see about that molex connector below it that was mentioned earlier and see what is going on at that junction.

Any other ideas of where this circuit may be going wrong? Thanks!

Tom

 

[Gunn]

SOLVED! Long story short, it was the connection right at the solenoid at the trim pump. Arghhhhh.

Now the long story: I removed two long screws on the throttle control that allowed me to remove the controls. To my surprise, they are actually in two halves...a port side half and a starboard side half sandwiched together. Once I pulled them up and out of the hole they were installed in, I followed the wires down into the abyss. Unfortunately there was no connector.

So now what?! I thought awhile on how I could get to these wires somewhere else and realized that I would probably be able to get to them from the starboard wall of the mid-berth. After removing some cushions, a bunch of screws and the side panel I was then able to look up and see the wires. Sea Ray used simple insulated butt-splices to join all of the wires from the throttle to the harness. But miraculously, I was able to see the identical blue/white, purple/white and green/white wires that I saw going into the harness in the engine room! They were wrapped in a 3-wire bundle, within the overall bundle going to the throttle. I was able to probe the green/white wire at this splice and confirm that I had continuity with the terminal at the switch. So that portion of the wire was fine. FYI, the blue/white wire ends up being routed to the trailer switch, that's why I didn't see it at the throttle buttons.

I couldn't understand it. I didn't see any reason why this wire would have failed in the harness/bundle. So I went back to the engine room and stared at the solenoid. I noticed some rust on the little terminals where the black (GND) and the green/white wire connects. When I had tested the solenoid, I jumped from +12V to the large terminal on the solenoid. This would then engage the solenoid and lower the drive. However, I did not jump the little terminal with the green/white wire (It's nearly impossible to get to).

I jumped +12V to this terminal. It sparked but didn't do anything. Tried again. Same. Tried again. Same. Then the 4th or 5th time, it sparked and engaged the solenoid!

I then removed the nut and lock washer and wire brushed all of the rust off of them and the wire ring terminal. I put it back together. Hooked up the switch at the throttle and tried it. Bam, it worked!

Now, whey the corrosion? Maybe I bought an off-brand solenoid or something. Since I have easier access to the trim pump with the starboard engine out, I'm going to replace the solenoid with an OEM Mercruiser brand, and then use some kind of protective spray or corrosion inhibiter on the terminal to prevent it from happening again.

Even though I completely tore up my boat unnecessarily to figure this out, I sure learned some things about how the wires are routed, and learned a lot about the throttle controllers. Now to put it all back together...

Thanks all for the help, and listening to me think out loud, it was very helpful!

Tom

 

[Gunn]

Old post I know, but I just wanted to put this here for anyone else that might want stumble across this gem.

I replaced the bezel around the trim switches on my helm control with the OEM part from Mercury: 19029T05, as mine was a bit chipped from trying to pry it off. To my surprise, this one had BOW UP and BOW down marked on it! My original one did not. This is fabulous, as I would always forget which way to push or pull the switches. I always think airplane...pull back and the nose rises, but that is opposite on the boat. And so then I'd wonder to myself every time...is it the same, or is it opposite. No more!

19029T05


Here it is installed:

Tom

 

[Mcole1170]

Old post I know, but I just wanted to put this here for anyone else that might want stumble across this gem.

I replaced the bezel around the trim switches on my helm control with the OEM part from Mercury: 19029T05, as mine was a bit chipped from trying to pry it off. To my surprise, this one had BOW UP and BOW down marked on it! My original one did not. This is fabulous, as I would always forget which way to push or pull the switches. I always think airplane...pull back and the nose rises, but that is opposite on the boat. And so then I'd wonder to myself every time...is it the same, or is it opposite. No more!

19029T05
View attachment 128263

Here it is installed:


View attachment 128264

Tom

Hey came across this old post. How did u get the new trim bezel to stay in. Same issue replaced mine but can't figure out what to use to get it to stay besides tape. Horrible design should've. Eem installed with set screw, tabs or something. Sage boating

 

[Jimmy Buoy]

I've had success with securing plastic like that with a product called "Marine Goop". Its near clear and doesn't yellow but stays kind of rubbery vs hard glues when cured. It is usually quite easy to remove the part in the future with a little prying then clean up the surfaces, reapply and glue it back together. Also, the unused tube can be put away and it usually is still useable for years.

 

[Mcole1170]

Thanks will check it out.