GPS Help-gctid826756

[otnman]

Hello,

Wife and I recently bought a 1991 Avanti 3055. It came with a Raymarine A65. The previous owner said he had hooked it up only once, but that it did power on. I tried and no power. I began trying to trace wires by myself and di not have much luck. I did find a couple of wires going to the positive post on the battery. One I assume for the VHF radio and 1 for the Raymarine. The 1 I suspect for the VHF had a 20 amp fuse that was good (but I assume this is way too much for just the radio) and the fuse holder was slightly melted on one end. The other that I think is for the Raymarine had a 10 amp fuse that was blown. I had brought with me a pocket full of old fuses and the closest I had was a 6 amp. It immediately flashed and blew (without the GPS connected). Reading through the Raymarine manual, it appears it should only require a 4 amp fuse. So, I assume I have a short somewhere. My idea was to just get a new power cable and run it myself and just tape off the end of the old one and tie it off. Also, reading in the manual I understand the negative and positive got to the battery, but where would I hook the RF ground to? I tried searching, but got overwhelmed with information that didn't really apply to my situation.

Thanks,

T.J.

[Centerline2]

First... a boat owner who has any desire, or more realistically, a need to work on the boats electrical themselves, has to have a decent multimeter to help troubleshoot circuits. without it, your efforts are closer to "guess work" than they are productive...

Second... the bigger the boat, which begins to have "systems" and many more wires involved, and has many times more potential for problems such as you are experiencing, having a short circuit finder/wire tracer is just as valuable.

these two tools would tell you everything you need to know to make a proper repair to the system, without the need to add more wires. and it would tell you within 5-10 minutes exactly where the problem is located.

if more boat owners invested in these tools, there wouldnt be nearly as many used boats with "spider web" wiring, and masses of wiring that apparently goes to no where...

as to your current problem, you really should find the short and repair it, rather than just adding more wires, as the shorted wiring could very easily have potential to damage other circuits, or be a fire hazard.

the RF ground connects to the batt negative, or to the dedicated bonding system if your boat has one. the wire is suppose to allow any wire "noise" that could build up in the electrical system to drain off into the battery, so that static noise thru the speakers and interference on viewable screens is kept to a minimum.

[otnman]

Thanks for the advice. I did have the multimeter to tell me there was no power to where the cable hooks into the unit. That's why I started looking at fuses. as far as the short circuit finder, is there 1 you would recommend? After having to put a new stereo in since the face on the old 1 did not work and seeing how the previous owner wired it I can see the need for that ( I still do not know how the stereo ever worked), as it does have the spider web of wires you talk about. I have never used 1, but they look fairly simple to use. Hopefully they are, as I am usually by myself working on this thing.

[Centerline2]

"otnman" post=826762 wrote:
as far as the short circuit finder, is there 1 you would recommend?.

I would recommend the Power Probe brand, as its a quality, proven unit at a reasonable price, and they have great customer service if needed.. but there are others that can be had for less than half price of the power probe, but I havent had any experience with these.

harbor freight also has one of the cheaper models...

all it takes to trace a wire or find a short is to disconnect one end of the wire, or if you are in the middle of the wire and would like to know where each end of it goes, you will have to cut it to connect, and splice it back together afterwards....

if you dont disconnect one end of the wire, it can backfeed and send the signal down other wires, causing confusion due reading on several wires....

after connecting, the transmitter sends a signal down the wire and the reciever picks up this signal wirelessly, and you only need to follow the beeping with the reciever until you find where it connects.... sometimes you cant pinpoint the exact terminal that the connection is made to, but it gets you within a couple inches and then the multimeter will locate the exact connection....

finding a short is very similar, but each model may have a slightly different procedure or beep pattern, but its just as simple.