Trim tabs

[Smiley1957]

Was curious if there is a problem with my trim tabs. When I push the buttons to raise or lower them, the tach. rpms bottom out. After I let go then tach resumes. Along with that the tach. doesn’t start showing rpms until way after we are under way. Then it only goes up to around 2000. Any suggestions ,ideas or comments would be greatly appreciated.

 

[alldodge]

Need to start cleaning connections from the battery up to the helm

 

[Tabman]

I'm with with All Dodge, but I'd start with the grounds! Faulty ground wires (particularly on the "boat side") cause so many of these type of issues!

 

[Smiley1957]

Thanks for the advice. The main battery switch was terribly corroded. Cleaned and put back together. Very hard to turn. Had to use channel locks to move it. Ended up buying a new one. That is a start. What to check next? Battery’s are cleaned and tight.

 

[alldodge]

Look at the starter post, more corrosion possibility. Best to remove the cables even if they look OK to be certain things are clean. Look at the cables, and under the insulation jacket. They can look good but be corroded under. Do this with the ground cables as well.

Pull the motor 10 pin connection and see what the ins look like. Under the helm see if there is a buss bar for ground and 12V connections, this is another place where corrosion happens

 

[Smiley1957]

I just purchased this boat about a month ago. Don’t know a lot about it as of yet. Had to put new o rings in the trim tab cylinders. I am more concerned about the reason the tach. Isn’t working correctly. But also concerned about the tabs affecting the tach. Apparently tabs are wired somehow to the tachometer,could this be the whole problem?

 

[Smiley1957]

Thanks . As far as the cables. Can those be bought according to length with fittings attached or do I have to buy cable and cut to size then add fittings.

 

[alldodge]

Apparently tabs are wired somehow to the tachometer,could this be the whole problem?

No, this would not be the case. If you have bad connections, which sounds like you do, when something like the tabs or the drive trim is activated, this pulls enough power to drop the 12V going to systems. This in most cases is cause tachd by a bad ground but can also be caused by the hot side.

The Tach wire comes from the negative side of the coil (gray wire). This wire goes through the 10 pin connector up to the tach. The tach may even have some corrosion on the connections which can cause similar issues

 

[alldodge]

Thanks . As far as the cables. Can those be bought according to length with fittings attached or do I have to buy cable and cut to size then add fittings.

You can order ready made, search for "custom made marine battery cables". There are several places. Can also find them ready made, just find the size and length needed

 

[Smiley1957]

Thanks for your help. Haven’t had time today to do anything with the boat, moving son back to Columbus for school. Hopefully I can get back at it Monday evening.