Sucked a mermaid into my water intake

[Siphon]

Just kidding. But I have a problem that’s equally weird.

Anybody have a standard accessory power wiring diagram for a Merc 5.0 Alpha 1 Gen 2? The boat is a ‘99 Sea Ray 210 Sundeck.

The problem I’m having is that when I hit the trim toggle, it shuts off my stereo. Up or down, both do it. Turns right back on. Trailer trim up does it also. And the trim pump is extremely slow, sluggish. Seems I have some combination of low voltage and a circuit crossed somewhere, but I don’t know where. Rechecked stereo wiring under the helm (it’s new, installed last week), inspected for frays between the throttle control and helm and found nothing. Battery connections are clean and new. I can’t spot an obvious bad ground on either the trim pump or any of the buss bars under the helm.

Don’t know where to begin. Checked for mermaid hair wrapped around the battery already, that wasn’t the problem. Thanks for your help.

 

[Rick Stephens]

Clean all your grounds first.

 

[achris]

...The problem I’m having is that when I hit the trim toggle, it shuts off my stereo. Up or down, both do it. Turns right back on. Trailer trim up does it also. And the trim pump is extremely slow, sluggish. ....

Sounds like the stereo is very voltage sensitive, and there's a problem with the trim pump motor drawing too much current and dragging the battery voltage down.

I'd be checking the current drawn by the trim pump, with a view to a strip and clean of the trim pump motor.

Or it could be a weak/old battery.

Chris.......

 

[gm280]

Maybe the mermaid you sucked up is causing a serious voltage drop at your stereo. :noidea:

 

[Jcris]

Just a thought, change the location of the hot wire that supplies the radio, if possible.

 

[Scott Danforth]

start at the battery, clean every electrical connection, terminal, post, etc. from the battery to the motor up to the helm ground buss and fuse block.

by clean, clean enough your motor would eat off them.

then seal every connection with marine electrical varnish.

 

[Siphon]

Thanks, all. The stereo got installed a week ago and everything was working perfectly for that first blissful week. However, I installed the new stereo because the old one was fritzy (had nothing to do with trim, just lost connection to my phone and kept shutting off/back on on its own) so evidently my diagnosis of the root cause was incorrect. Batteries are 3 year old good quality AGM, separate dedicated house and start batteries. I’ll check them nonetheless.

I’m looking for ideas about anywhere else the trim pump and stereo would share a supply, ground, or just be in proximity. That’s why I asked if anyone could direct me to wiring diagrams. I have a basic trim pump diagram. And I have the engine side of the main plug diagram (below). But don’t seem to be able to find a general idea of where things go on the other side of the plug.

 

[Rick Stephens]

Look in the appropriate Merc Service Manual. It has wiring diagrams in it.