Trim/Tilt Button Voltage Drop

[Waytam]

I have 218 ls Monterey with a Mercruiser 5.0. When I press the trim button on the contols the gauges ( Fuel and Voltage ) drop as if the key is off. I have a feeling that I have a grounding problem somewhere but don't know where to start. I put a volt meter on both batteries and am getting 12.8 and12.7 at the batterries. What wiring should I look at first the find the problem? The tilt trim works fine but pressing the trim button causes the voltage drop.

 

[Don S]

Re: Trim/Tilt Button Voltage Drop

Check your battery cables. They need to be in good shape, clean, and TIGHT. Throw the wingnuts away and use regular SS nuts.

 

[Waytam]

Re: Trim/Tilt Button Voltage Drop

i dont have wingnuts just a standard SS nut as you sugested. Battery cables look good with no corrosion what so ever.

 

[Don S]

Re: Trim/Tilt Button Voltage Drop

What drive and year are we talking about here? Doesn't matter what kind of boat it is. Is your trim button on the thottle handle?

Typically, the trim pumps are hooked directly to the battery, and the trim button is powered from the pump. Shouldn't have anything to do with the instruments.

 

[Steve91T]

Re: Trim/Tilt Button Voltage Drop

Is it possible that your alternator and/or battery aren't as good as they used to be and they just can't handle the load? My guess is the whole system is taking a huge hit, causing some of the gauges to drop off line.

 

[Waytam]

Re: Trim/Tilt Button Voltage Drop

2004 alpha one The button is on the the throttle handle. The radio ( Sony ) also cuts out when the trim button is pressed. I tried disconnecting the amps from the batteries completely and the gauges still drop. I was told that that a Sony radio will shut of if the voltage drops to low.

 

[Don S]

Re: Trim/Tilt Button Voltage Drop

Lots of things will drop out if the voltage is too low. What happens when you try to crank the engine over?

Get the batteries charged and load tested.

 

[Waytam]

Re: Trim/Tilt Button Voltage Drop

New batteries and put then on the charger/tester that I have and where 100%.

 

[Don S]

Re: Trim/Tilt Button Voltage Drop

Does the engine crank over? Here is the trim troubleshooting chart and wiring diagram.

View attachment A1G2 Trim Troublelshooting.pdf

 

[Waytam]

Re: Trim/Tilt Button Voltage Drop

Boat cranks and runs with out any problems I have taken it out a few this year with this and the power outlet the only issues. The power outlet on the dash does not work. Thanks I will check out the chart.

 

[Don S]

Re: Trim/Tilt Button Voltage Drop

Since the engine starts, it's not the battery cables. How it affects the gauges is strange, and I have no clue why.

You will have to find the power wire going to the trim switch and figure out where it gets power from. Obviously from the instruments somewhere.
Was everything working fine one day and then just started this, or was some other work being done on something else? Stereo, or electronics installed? New light or something?

 

[Steve91T]

Re: Trim/Tilt Button Voltage Drop

Boat cranks and runs with out any problems I have taken it out a few this year with this and the power outlet the only issues. The power outlet on the dash does not work. Thanks I will check out the chart.

I had a boat that had 3 power outlets, one worked. I think they just get corroded. What about the alternator? I've dragged my boat over to Advanced and had the battery tested along with the alternator for free.

 

[Waytam]

Re: Trim/Tilt Button Voltage Drop

Everything was fine when I used it last summer. First time I used it after it sat through the winter this started. The only I did was put the freeze plugs back in and put two new batteries in. I put new batteries in it every spring before I start it up.

I can understand the gauges if the button is getting power from them but the radio cutting out as well seems strange.

 

[Waytam]

Re: Trim/Tilt Button Voltage Drop

The altenator works fine. I disconnected both batteries with the motor running and it stays running. I also put a volt meter on it and am getting over 14 volts.

 

[Don S]

Re: Trim/Tilt Button Voltage Drop

The altenator works fine. I disconnected both batteries with the motor running and it stays running. I also put a volt meter on it and am getting over 14 volts.

:facepalm: :facepalm: :facepalm:


That may have been a test for generators back in the 50's on cars, but you don't do that on alternators.

 

[Waytam]

Re: Trim/Tilt Button Voltage Drop

Why is that is it bad for the altenator?

 

[wellcraft-classic210]

Re: Trim/Tilt Button Voltage Drop

1 suggestion

Do you have a ground wire coming off your alternator to the motor mount ? Or any other places on the engine?


I ask as my merc 5.0 does and it was loose when I purchsed the boat. And its pretty well hidden. That was causing some intermittent issues like you describe. I ran a redundant ground wire to the gage panel ground in the process of elimination. That got things working and help me to pin point it.

My starter & engine worked fine as it uses its own ground cable to the battery.

Could be in the harness as well but again try the redundant GND wire to verify a gnd connection issue. Just make sure its large enough gauge as the originals to handle the current. ( 10 gauge I think )

 

[hanagansny]

Re: Trim/Tilt Button Voltage Drop

I replaced my ground cable from the battery to the block. That fixed this problem for me. Good luck.