More Trim Tab Troubles

[Dream Weaver]

Hey guys,

I recently installed a brand new set of Bennett tabs. Everything is brand new, no broken or corroded components. I took the boat out this past week and had an issue.

When I power the boat on, the trim tab display lights up; however, when I was underway, as soon as I pressed the buttons to trim down, I lost power to to the tabs. Display shut off, nothing up or down.

I my first thought was that I blew a fuse. So I brought the boat to a complete stop, shut the motor down, and turned the battery switch to the off position. Gave it a minute, turned the battery switch back on, fired the motor back up, and the display came back on. Everything lit up as if it were ready to go again, telling me that the fuse is fine. Got the boat up to speed again, went to trim down... again, lost power to the tabs/display.

The only thing that makes sense to me, is that I am getting a voltage drop when I put the tabs under load, causing them to cut out. But I am perplexed, because I just recently charged up my batteries and I have the tabs wired to my number 2 battery which nothing else is running off of. They essentially have a dedicated battery.

Any thoughts or input appreciated.

Thanks.

 

[Hookup1]

It's behaving like a battery problem. Put a voltmeter on the battery and try the trim tabs. Move the trim tabs to the other battery with a jumper for testing and try them.

Check crimps. Make sure your ground wire is solid. Check the positive wire as well. Ground wire is a common problem but yours isn' behaving that way.

if it is the battery check that it is getting proper charging voltage. Battery should be about 12.8 VDC and 13.1 VDC when charging. If not charging check charger fuse - another common problem.

 

[seasick]

Try deploying the tabs at idle, not in motion. If they work that means the pump is working. When under way, there is a lot more force on the tabs. I suspect a wiring issue as Hookup mentioned. What guage wiring did you use and did you run a separate ground wire also?

 

[Dream Weaver]

Try deploying the tabs at idle, not in motion. If they work that means the pump is working. When under way, there is a lot more force on the tabs. I suspect a wiring issue as Hookup mentioned. What guage wiring did you use and did you run a separate ground wire also?

From the control switch at the helm, I have a 12 ga positive and negative that both go straight to the battery. There is also a smaller gauge ground wire that comes off the back of the hydraulic power unit that I have grounded to the negative terminal of the battery.

 

[Dream Weaver]

I do have a few extra feet of wire, both positive and negative, that I ended up just coiling up instead of cutting since I had already attached the heat shrink ring terminals. I overestimated the run that I was going to need to make. This could also potentially cause a voltage drop? But I doubt it, because the entire length of each wire is only 10 feet, which I don’t believe is too long for 12 awg.

 

[Hookup1]

View attachment 29458
I do have a few extra feet of wire, both positive and negative, that I ended up just coiling up instead of cutting since I had already attached the heat shrink ring terminals. I overestimated the run that I was going to need to make. This could also potentially cause a voltage drop? But I doubt it, because the entire length of each wire is only 10 feet, which I don’t believe is too long for 12 awg.

The extra wire is not the problem. Wire gauge is fine. Get a meter on the battery and check voltage while you try to move the tabs.

 

[Dream Weaver]

Took a voltage meter to the battery and ran the tabs… battery read 12.6v initially, then as the tabs were lowering, creeped down to 12.2v and then shut off.

Granted, the engine was not running; but, it was acting the exact same as the other day when the engine was running.

 

[Hookup1]

Took a voltage meter to the battery and ran the tabs… battery read 12.6v initially, then as the tabs were lowering, creeped down to 12.2v and then shut off.

Granted, the engine was not running; but, it was acting the exact same as the other day when the engine was running.

Move the terminals to the other battery.

How old is that battery? Checked water level lately? 12.2 volts is not good. You may have a bad cell.

 

[SkunkBoat]

idk what the problem is but...
Is that green wire right? Should'nt the +12v wire be orange from bennet tabs?

I don't like green wires on positive terminals.

 

[Hookup1]

Probably ran home run to the battery. Not the best choice of colors. Should at least shrink a red and black on the cable. Over time you forget what you did and invite reversing them when you need to pull the batteries out for some reason. I've done it because of previous owner. Burned up a harness but fortunately it wasn't a big deal.

 

[Fishtales]

switch it to the 2nd batt and try it.

 

[SkunkBoat]

Probably ran home run to the battery. Not the best choice of colors. Should at least shrink a red and black on the cable. Over time you forget what you did and invite reversing them when you need to pull the batteries out for some reason. I've done it because of previous owner. Burned up a harness but fortunately it wasn't a big deal.

I don't care how much wire costs, you don't use green or black or yellow for Positive battery connections. I understand motor cables are always black and have a red heat shrink to identify the Positive lead.