100 AMP Solenoid

[td in nc]

I am trying to install a dual battery switch and I am having an issue trying to figure out if the 100 Amp solenoid is required on my 2000 Launch. At first I thought it was something the PO installed for the stereo, but following it back it the wire goes to the wake plate control on the dash. Is the 100 amp solenoid required or was this for something else, as it looks like a non-factory install?

solenoid.jpg

[CJD]

A solenoid that large would usually be used for a battery separator. Did your boat have dual batteries to start with?

Wait...just looked at your picture. That is, indeed, a battery isolator. It should, directly or indirectly, have a lead to each of your batteries. When the primary battery is charging, it should close to also charge the secondary battery. When the charging stops (i.e. engine shut down), the solenoid should release, isolating the secondary battery to use your radio and other equipment without draining the primary starting battery.

There may also be a wire to the dash with a switch to manually close the solenoid for a 2 battery boosted start.

[td in nc]

yes but the PO switched it so one battery was dedicated to the boat and the other to the stereo. So if you have duel batteries you should have a solenoid?

[Smitty75]

I'm not positive of your exact setup, but a lot of people use a solenoid in place of a dual battery switch. If that's the case it Would have nothing to do with the wake plate other than he used that as a 12volt source for the solenoid. It's basically an auto isolator for a dual battery setup.

[CJD]

We're playing post tag! I edited my first post. If you look at the name on the relay and google the name under "automatic charging relay", you can get a copy of that solenoid's instruction sheet. It is very simple. One post is for the primary battery for starting (although with some models it does not matter which is primary) and the second is for the secondary battery. Another small connector is to ground, and the second small connector is for manual boost start.

It is fully automatic.

[td in nc]

thanks this is helping. So should be just able to tie the power wire from the wake plate to the one of the power sources. I am stalling a perko switch for the two batteries, and one battery (set on bat 1) everything works correctly. Then when I switch to bat 2 weird stuff starts happening to the gauges, the fuel pump kicks on the kicks off, when I try to turn it over I just hear clicking. Check both batteries and they read just over 12 volts on the multi meter. The image below is the set-up I am trying to reproduce, except not running fuse box back to battery.images.jpg

[td in nc]

Note on my previous reply I am not using the solenoid.

[CJD]

There could be a few issues to cause what you are describing.

For one, the charge solenoid may have failed, so the second battery is not charging. If you have gotten rid of it, then that already solved that problem!

Another possibility is that, with the "different" routing of the cable through the wake plate...you may have some odd items on odd batteries. The normal mode would be to have the stereo and non-essential items on the secondary battery. The engine run, gages, starting and bilge should go on the primary battery. Anything else is pretty optional, like wake plates and ballast pumps. The PO could have done, literally, any combination.

Finally, with the indirect battery cable routing, you may just have a poor connection somewhere causing the issues.