Paging LUKE or whoever is good at 12v electrical

NYSpeed Automotive
1

I have a boat, the gauges and electrical are incredibly difficult to get to, but I removed the windshield and the cowl so the majority of it is currently exposed. It’s still very difficult to reach a lot of the connections hence why I’m trying to solve this issue as intelligently as possible.

So about 6 months ago, my motor tilt/trim gauge started bouncing around and wouldnt hold steady, a month later, it stopped all together.

This past week, I took the boat out, and when I trimmed the motor down (with no gauge) the radio stopped playing.

Then during that same trip intermittently the radio would go on and off randomly. I bought a new radio and am going to be rewiring it, but the grounds are wired in series (i think… its ground from radio, to tach, to speedo, to fuel, to trim, to ground block)

On a separate note, my GPS shit the bed this past month too, so I got a new one as well (the old one had about a cup of water inside it… needless to say its trashed, and rightfully so at 15 years old)

Could all these issues possibly be based on a short in the GPS? I feel like they’re all a ground issue. Would it hurt to run alternate grounds from each of the gauges?

Any help to speed up my guess work would greatly be appreciated

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some pictures

https://scontent-a-mia.xx.fbcdn.net/hphotos-ash3/t1/1176113_10101553085426308_31950627_n.jpg

FRONT (on a separate note, i bought a 7 inch gps thats not made to flushmount without 8 inches of room, that cutout in the dash is way too small to accomodate the newer style GPS’s, anybody have any ideas to get one in there without having to reglass everything, i certainly dont want it to look like garbage or to not seal up)

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc1/t1/1507900_10101553086349458_796848035_n.jpg

RATS NESTS

2

Nothing looks terribly out of whack. Find your main grounding point and make sure it’s tight and clean. If you can get a multimeter that will really help you debug it. For the bouncing gauge it either has a bad connection or the gauge is fried. If you can get the gauge apart look to see if any components look bad.

It would be a good idea to add or relocate the grounds if they are all tied together. A ground CAN be connected at multiple points giving the appearance of being in series so long as the wire is rated for the total current for all the circuits. Look for charred areas that were likely caused by arcing.

3

Ok, i have a multimeter, just not sure what to be testing with it. Tools are easy to acquire, knowing what to do and set it on is my challenge. No real charring, a little oxidation on some of the wires. Getting the trim gauge out may be a challenge, but I’ll try and pull it out tomorrow.

Thanks for this help

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Right now it looks like this… Ground block ------> trim -------> speedo ------> gps ------>tach ------ fuel ----- clock ----- radio

All work fine. except the trim. (or the radio when im actually pressing the trim up/down switch… and even this is intermittent)

As for the trim gauge, when i turn the ignition on, it indicates the trim is down (when the trim is up) when I trim up, the gauge moves slightly but when the button is released indicates the trim is down again

even if the outdrive is straight up

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EDIT… the ------ indicate the ground wire

4

If you are concerned with the ground there is nothing wrong or particularly difficult about taking all of them apart and running them to a ground block then to ground. this will isolate the individual components and give you a good starting point. Just to cover it, my knowledge it is based on non low voltage circuits.

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Also if these are all 12VDC devices and some are aftermarket, you could be overloading the circuit.

5

Up to this point they were all factory equipment.

molded dashes make me angry. I wish it was a standard flats boat with normal console/starboard.

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is it bad to have 2 grounds going to one gauge? is that a big deal or a big no no?

6

It should be fine, just make sure they’re clean like Luke said. The water in the GPS could defiantly mess things up if they’re all connected. Put the multi meter on dcv 200.

7

So far all that has been said has been good advise.

But… if that were my boat; and I’m anal-retentive about details… I’d be tearing all that wiring apart and installing a bunch of these:

[ATTACH=CONFIG]25623[/ATTACH]

And making it look a lot more like this:

http://www.floridasportsman.com/files/2011/08/Shipoke_18_13.jpg

This way I can track any/all wires & signals; add things easier, and troubleshoot things a lot quicker. Not to mention it’s a lot cleaner than jumping between everything.

8

My fuse block has some bad terminals on it so rather than switch a bunch of wires I’m going to replace it and try and label things more clearly. I may even change the style connector just to be safe. Well see. I’m thinking it may be a bad ground from the actual sender because my gauge is getting power and seems to be functioning (just not properly)

9

Put in new fuse block… A bunch of broken switches work now. Unfortunately still no trim indication.

Sigh. Time to start running jumpers around.

10

It sounds like the grounds are just piggy backed. Meaning the wire ground wire is tied to the next gauge in series to continue to boat ground. Nothing WRONG with it unless the wire gauge is too small which could be part of the problem. I would use a terminal block like the one posted already and use a jumper strip to tie all the circuits together to one main ground.

With your meter you can test for a Voltage on the gauge itself. Just touch the POS and NEG on the gauge and see if the meter pick anything up. If not, do a continuity test using the ))) symbol. Touch two points to see if it is connected.