Garmin Problems

[Bright Eyes]

This is for those sailing electricians out there. I've been stuck on this Garmin Install for a month now!

Ok so the I have a Garmin 441s. The power wire for the Garmin isn't long enough to reach the control panel so I spliced an extension on to it. I plugged it in and it worked great.

But then after I ran the wires through the pedistal guard and cockpit floor to the control panel it wouldnt come on. The volt meter at the panel flickers back and forth and some times just sits on 0. At one point it kept enough voltage to turn on and I was able to check that my transducer wire worked after I spliced it. But then the voltage flickered and it turned off.



Troubleshooting I have done:

I respilced the extension wire as clean and firm as possible.

I unplugged the Garmin and used a volt meter to check the voltage at the breaker, it was 13.5v. I checked the voltage at my splice and it showed 13.5v. I used the resistance meter to find which of the 19 holes in the Garmin plug belonged to the red and black wires and test the voltage there, 13.5v.

I checked the plug and none of the holes appear damaged. Nor are the spokes on the head unit side.

I took the Garmin head unit into West Marine and plugged it in with their wires and it came on fine.

I connected the power wire to another new circuit breaker.

When I plug in the Garmin and use a volt meter at the circuit breaker it shows only 7.5 volts. I then checked the voltage at the splice and it showed 7.5 volts. And ofcourse I can't check the voltage at the plug during this because it is plugged in.

I do all this with and without the transducer plugged in.


SO... what's wrong?


Thanks!

[senormechanico]

If the voltage at the breaker is only 7.5, look upstream from there (toward the battery).
You probably have a corroded connection.
Don't forget the ground connections either.

[Bright Eyes]

Yes, there is a grounded wire.

I will try taking out the breaker and reinstalling, but I tested other appliances such as a spare bilge pump on this breaker and it worked fine. I will also try to connect the Garmin wire to other breakers that already work for other appliances.

However, the other appliances, such as cabin lights, all work fine so it would be interesting that there is a problem with the battery connection.

Thanks for the suggestion.

[btrayfors]

There are only a couple of possibilities, given your description.

Given that there is enough battery power available (other items work OK without drawing down voltage much);

Given that a shorted Garmin unit would likely blow internal or external fuses;

Given that the wire size is adequate for the length of the run;

Then.... there HAS to be a high resistance point somewhere: wiring, connectors, crimps, etc.

Since you've checked the connections pretty well, my bet is that you managed to cause a partial break in the POWER WIRING itself....maybe when you pulled it thru the pedestal. This would account for the proper voltage reading with no load (13.5V), but the very low voltage reading when you turn on the Garmin.

This happens because there's practically no amperage draw for the volt meter, but the power wiring is unable to support any real load...even a pretty small one.

JMO,

Bill

[Bright Eyes]

Could the high resistance point be at the splice? I spliced the extension on by twisting the wires together (black to black and red to red) and then soldering them.

I used 14 guage wire when I redid the extension to make sure it was enough. The Garmin power wire is about 16-20 gauge.

I really didnt want to pull out the wires cuz it was kinda a hassle but I guess I will have to. Running down and through the pedistal guard is the Garmin power wire, the transducer wire, and the autopilot wire and they are a tight fit through the cockpit floor hole. Is it possible they are interferring with each other even tho they are each in their own wire casing?

I will take the wire out then and check for damage. Will a restance point be noticable?


Also I removed the 3 amp fuse when adding the extension, since it was goin to a breaker.

[btrayfors]

Put the 3A fuse back. It is designed to protect the 441S, not the wiring. FYI, the 441S draws a maximum of 15 watts (1.25A @ 12V).

If, indeed, there is a damaged wire it's most likely in that portion which was drawn thru the hole, as you say it's very tight. No...proximity to other wires isn't a problem, but crimping and stretching the wire when you pull it IS a problem.

I'd verify first that the wire from the Garmin is OK (you have to cut into the wire near the splice...in fact, you'll want to replace the splice. If the unit works OK when connected at that point, then I'd replace the extension wire thru the pedestal. A high resistance in the damaged wire could be hard to detect, since resistance and continuity measurements could be "normal" .... they don't require any real amperage. You'd only notice the resistance when a load was applied.

Bill

[senormechanico]

If between a known good ground and the breaker, you have only 7.5v, the problem has got to be between there and the battery.

[Brent Swain]

I found Garmin's warrantee as useless as a one legged man in an ass kicking contest. Buy your electronics from some large chain store with their own warantee, not a small shop which leaves you dependent on Garmin.

[Bright Eyes]

i removed the wire from the pedistal guard and cut off the spliced extension. i connected the Garmin power wire to the breaker and it showed 7.5 volts. All the other appliances show 13 volts. When I connected the Garmin wire to one of the other working breakers it then showed 7.5 volts.

There must be something wrong with the Garmin power wire then right? There is no visible damage.

[btrayfors]

Probably. I'm in the area. PM me for phone # and I'll try to help.

Also, expect to be at Herrington Harbor North on Sunday, and maybe could help if needed.

Bill

[Highlander40]

While I don't think that this is causing the low voltage.
Twisting and soldering wires is not good on a boat. It creates a hard spot in the wire and the strands will eventually break near the solder.

Marine grade crimps with heatshrink covers is best.

If the battery and breaker are good.. when you get 7.5V... the wire should be hot. Not a good thing, just indicating a huge current draw or small wire gage. The extra wire you added should be heavyer than the Garmin wire too.

If you can measure current you will have the answer.

There are only three possible problems

A. the Garmin unit is toast.
B. your batterys are toast
C. the wires are corroded, loose, too small etc.

Of course there is one more, you have wired in a short on the Garmin unit.
But then the wires will be making toast.

[Highlander40]

Oh yeah, Bill is right about the fuse, put it back before anything else is done. Breakers have one function ONLY and that is to protect the wires ,not the expensive stuff on the end.

Another thing, the point where you measure low voltage is AFTER the weak connection. Unless you have a short. then you have hot wires.

[Bright Eyes]

Thank you for all the suggestions! I feel like this electrical problem was almost a good thing as I have really learned alot in the past month about electrical connections.

So since my last post:

I checked for resistance in the Garmin power wire and found none.

I took the Garmin and the power wire to West Marine and they hooked it up and it came on fine, so it was confirmed that the problem was on my boat.

I took out the breaker and connected the Garmin power wire directily to the power bar in the conrtol panel, and still got only 7.5 volts.

I connected the Garmin power wire directly to the 12v Battery itself and I got 13 volts and it came on.

This narrowed the problem down between the battery and the control panel. So I got behind the control panel and check all the wires and tested voltages at various points.

Eventually I found that the original grounding plate on the boat floor had a loose bolt on it!

So I tighted that grounding bolt and tried again at the control panel and Bingo! it came on.

I can now finish this project and fail at something else

Thanks again to everyone, CF continues to be a wealth of knowledge!

[Highlander40]

Great to hear the positive wrap up.
Everybody that follows these stories on CF wants to find out how it all played out. Like a mystery novel.

Thanks and fair winds!

[senormechanico]

Another bad ground bites the dust!