Garmin Fishfinder 125 inoperative.

[newbiedmv]

I have an old  Garmin fishfinder 125 that does not turn on. It was installed with the boat. I've checked just about everything so far ( with the exception of a 2 amp fuse Garmin recommends, I have yet to find it with the console apart) . There is no voltage at the connector nor was I able to find a ground ( retired electronics person). I have looked but can't seem to find a pin out of the cable and due to the boat( Crestliner cx17) tracing is very very difficult.

At this point I've lost power and ground ( I used the cigarette ground as a reference). No help from Garmin so far. Anybody have a clue where I can get some info?

I wouldn't mine putting in a better one and plan on looking into it, however I'll have to have it installed which from what I want would be very costly ( 2 hook ups, one console one bow). 

Any info would help out a lot.

Thanks

[Way2slow]

I don't understand why you would even think Garmin could help if you are not getting power to the unit.  They don't have a clue how you boat works.  If there is no power to the unit, that's a boat problem.  If you have an electronics background I would think you would have a VOM or multimeter of some sort and know a little of how to use it.  

My basic rule In trouble shooting, is to go from a known good to the unknown.  Meaning, your only known good source for a battery negative (ground) is on the negative battery post and the only known good positive source is on the positive battery post, so you should start there and work out from there taking voltage readings at different points until you get to where you need the voltage.  

You should do each side that way.  Leave the negative test lead on the battery and check for positive voltage at different points to see if you have it all the way or where you are loosing it.  

Then do the negative, leaving the positive test lead on the positive post and move the negative lead to different points to ensure you are getting a reading and you have a ground all the way to where you need it.

That 2 amp fuse you are looking for is usually on the power cable going to the unit.  

Never heard of a 125 but my first thought is, with possibly a 20 year old unit, I would consider just tossing it and getting something a little better, but until you figure out where to get power to it, another unit is not going to help.  I'm surprised the display isn't so black you can't see it anyway. 

[newbiedmv]

Yeah, I do have a  good DMM and checked it out correctly. I avoid the techno talk as it puts people to sleep. I'll have to make up a long cable to the battery for a ground reference.  One thing came to mind while sleeping. The Fuse block is really hidden away and very hard to get to but due to two many wires going to it and color of many of the wires ( to many Black ones) it's also a power and Ground Buss bar connection. Also  all the wires are bundled with zip ties everywhere so there is a possibility that there is an inline fuse in there. So cut the zip ties, look, check the buss, keep tracing, and if all else fails try calling Crestliner. Although for the life of me I can't see why they would have it buried under the deck somewhere. No indication of mice or squirrels.

 

Thanks a lot for the reply I didn't expect any at all.

Oh, yes the display is terrible. I have another one from the 90's that I liked and can rig up in a hour or so. I'll check the display out in the garage with the lights off, many it was coming on and I couldn't see it. Won't be the first time.

[J Francho]

I'm sure you looked, but graph fuses are usually inline, not on a fuse block, and I like them closer to the battery to make it easy to check.

[Johnbt]

The fishfinder 125 is the OEM boat model number for Garmin's fishfinder 120. They added a 5 to their standard model 80, 90, etc. 

 

https://static.garmin.com/pumac/FishFinder120_Installation_QuickStartGuide.pdf

 

copyright date is 2003 fwiw

[Way2slow]

My problem is, I have a degree in electronics, and have been involved in electrical and electronics trouble shooting for over 50 years from very sophisticated equipment to industrial maintenance and very good at it.  So, if I sound a little short and sarcastic, I really don't mean to be, I'm really not that type.  It's just what seems simple basics to me, having done it most of my life, is probably not even in someone else thought process 

 

I have several old LCD units that still work, but are basically unusable because of the displays turning black on them.  Some are only a few years old.  I just pitch them on the shelf with the other junks that I can't seem to throw in the trash, and get another.  

[newbiedmv]

Ok.fixed... yep the 2amp inline fuse was blown. Where was it....in the middle of a massive zip tied bundle behind the fuse block. Also the ground was very loose. All working now.

I also am a long retired EE and repair tech while in school but I've forgotton 90% of my stuff. I still remember ohms law and how to use a meter and soldering iron.

In any case had to fix the speedometer hose anyway

[J Francho]

Good news!

[cyclops2]

If you can not find a a hot wire or fuse ? Or a ground wire ? 

Stop wasting time & frustration !!  Pull a new pair of them. Install the fuse at either end of the POSITIVE wire.  Done. PLUS You will instantly know where to look in 1 second

 

   Enjoy   ?