How do you fix?

[cdog]

When the voltage gauge drops when you trim or use the tabs. Whats up with that? Everythings tight on the batt. I'm not sure what else to check.

[phebus]

Check all your grounds.

[CrazyHippy]

Or it could be that the trim and tab motors are working and using up some juice....
Run a voltmeter directly to the battery and have some one turn the motor over, :jawdrop: :supp: ;)
It's normal.
BJH

[Tom Brown]

How much does the voltage drop?

[RiverOtter]

When the voltage gauge drops when you trim or use the tabs. Whats up with that? Everythings tight on the batt. I'm not sure what else to check.
:idea: That's usually a great indicator of when to trade for a new one :D

[cdog]

All the trim pumps are new and do the same thing. I also have noise from any switch into the stereo while it's playing. The trim pumps get their power from the starter where the batt. cables meet them on the mercruiser fuse dealio. The gauge shows about 13 volts when the engine is running and drops to about 10-11 when I use the trim. It will idle ruff as the msd box notices the voltage drop. I also ran the grounds to the cast iron engine mounts and the added an extra 4 ga. ground on the port side batts. that are for the stereo only. I have plans on running a new + wire for the head unit to get rid of the acc. buzz and pops. What now? Do I isolate the trim pump + wires to a dedicated + block?

[Waist Deep]

Had the same problem and ran the ground right to the battery

[ROZ]

How much does the voltage drop?
Sounds like he needs a 50farad cap on his tab pumps :D Should add a fan too... :D

[phebus]

Caps. cure everything. In fact, I just cured an overcrowding issue on my workbench by taking a cap and throwing it in the trash. I now have 1.0 farad more space. :D

[ThongMagnet]

Most boats run best if you can isolate the (trim pump/ tab motor/ starter) from the stereo. This is usually done by adding a second battery and a dual switch. One of the batteries is a "cranking battery", and the other is a "deep cycle battery" (slightly larger), to run the stereo/gps/radar/etc.
Remember to always use a marine battery. There is a safey device built inside marine batteries, that is not found in a car batteries. :argue:

[phebus]

Remember to always use a marine battery. There is a safey device built inside marine batteries, that is not found in a car batteries. :argue:
I think the safety device you are referring to, is that you can expect to pay at least twice as much for anything "marine" :D

[cdog]

Most boats run best if you can isolate the (trim pump/ tab motor/ starter) from the stereo. This is usually done by adding a second battery and a dual switch. One of the batteries is a "cranking battery", and the other is a "deep cycle battery" (slightly larger), to run the stereo/gps/radar/etc.
Remember to always use a marine battery. There is a safey device built inside marine batteries, that is not found in a car batteries. :argue:
I've got two optima blue starting batts for the boat and two blue deep cycles for the stereo. Mabey i'll add a + cable to a dist. block on the transom and run the trim pumps to the block meanwhile keep all the engine acc. running off of the starter pick up.