Wiring nightmare

[TOPFROG]

Well gang....Over the weekend, I spent maybe 16 hours under the dash of this old 1990 Parker MV trying to unravel 17 years of wiring abuse.....With some success I might add - but sadly, not the progress I'd hoped for Previous owner only added new wires - never removed the old ones. I've got more dead ends than Washington DC.

I do have 2 questions some of you faithful could help me with....On the boat transom, there is a Pisco (sp) switch (two positions - on & off) under the port seat that, once placed in the "on" position, causes a fuse block under the dash to get power and things such as GPS, VHF, AM/FM, cigarette lighter and misc other "stuff" can be used.

Under the starboard seat is another switch with 1,2, ALL & OFF.....Now I know that is the switch that directs power to the motor (one, two or both batteries).....I also thought it would route power to the main switch panel on the dash - nav lights, wipers, horn, raw water, cabin lights, etc......

Well, not on this tug - the toggle panel stays hot all the time. Is that the original design or am I right and it should be dead when the switch on the starboard transom is in the off position?

Second question. When the AM/FM radio is on and/or the VHF, all is as expected. Turn on the GPS and that's the end of listening to either radio comfortably - tons of static Called Garman and they said most likely a poor ground on the GPS....Well, part of that 16 hours under the dash found the GPS wires and I can tell you, there's nothing wrong with the ground or hot wire connections. Removed them, polished them and verified 12.3 volts and good ground. Any thoughts????

Thanks Gang,

 

[Bryan 2530]

I have the same problem on my Parker with the GPS and FM radio. I tried two different antennaes and the reception improved but still same problem with the GPS. I was thinking some type of filter was needed. I am stumped because I though a GPS only receives not transmitts.

Anyone else have these problems?

I usually rig my boats to kill ALL power to the rig through the battery switch, save for an auto bilge pump if you want to. I usually prefer not to run an auto bilge but most people do.

 

[TOPFROG]

Thanks Bryan.....In my conversation with Garman, I was told the GPS antenna transmits NOTHING....It is simply a receiver. I was also told that Radio Shack sells a noise filter (called a choker I believe). Was told to put one on the GPS positive feed - if that doesn't solve it, then also put one on each radio and that surely will "fix" the problem. I wanted to see if there was someone out there that understands what's going on so I can fix the problem "correctly".....If filters is the correct way, then I guess that's what I'll do.

 

[Outta Here]

I had similar problem on my 18. VHF sounded less than perfect. You might be right about ground problems. Radio sounded great with boat in water. Maybe not really grounded out of water?

 

[DaleH]

The toggle panel stays hot all the time. Is that the original design or am I right and it should be dead when the switch on the starboard transom is in the off position?

I'd say your choice, but once you said 'AM/FM' radio, if a modern type, I bet the owner placed it on that circuit so that there is some power to the head so it remembers the pre-set stations. That circuit saounds after-market to me, i.e., installed by previous owner. My '92 had nothing of the sort.

IMHO as long as everything on that circuit is a true 'on or off' item, then are less likely to have any unknow amp draw which could suck the life out of your batteries. So ... to which battery is that switch tied into?

Also, I'd mount that switch in a tupperwear 'box' or similar mounted on the inside if the transom. Take off the lid, mount the box, mount the switch, cut holes in side of box for leads, add rubber gromments, attach leads (using plenty of dielectric grease), install t-ware lid. Cheap, foolproof and waterproof ... and simple!

A 'classic' CP DIYer project !

When the AM/FM radio is on and/or the VHF, all is as expected. Turn on the GPS and that's the end of listening to either radio comfortably - tons of static.

OK, you can get static not only from grounds but from cross-talk on the power leads. Your leads to each unit should be twisted, at least 3-twists per inch, as this minimizes interference. They (wiring runs) should also be routed as FAR AWAY from each other as possible, even if both head units are mounted in close proximity to each other. Bring one run up one side of the helm console and the other up the far other side.

FWIW I totally stripped out and re-wired my '92 once she was mine ... but I had to , as kids had vandalized her and cut every freakin' wire, hose, or whatever on board the boat. I essentially bought her as a complete DIY rebuild, if not salvage project.

 

[TOPFROG]

Thanks Dale.....I'll try your suggestions in a couple of weeks when I get back from Bulgaria (work assignment ).

All three devices (AM/FM radio / VHF and GPS are on the utility circuit (on/off switch - port side) and they do not have power when the switch is off (presets are lost on AM/FM). That switch is associated with the port side battery.

As long as I'm asking questions - Dale, how do you successfully mark wires? Do you use number rings and keep a master list somewhere on the boat (where to get the numbered rings)? I've tried to mark the wires I've added (trim tabs / lighter socket / Sonar) and don't like what I've done.....Works, but really adds to the clutter under the console.

Thanks,

 

[DaleH]

How do you successfully mark wires?

I guess it can add clutter, but I make SURE to put the ones on the wires in different spots, so all the labels aren't in one 6" square inch area surrounding the e-panels.

I also use the label machine to mark to the side of the panel or buss bar. It will list the item AND the fuse amp rating, like VHF 10 or GPS 3. Nothing like having the info right up front!

 

[TOPFROG]

Thanks Dale......I'll go for that - love the amp approach on the label!
:lol:

 

[TOPFROG]

Bryan A.....I stopped by Radio Shack on another venture and while there inquired on the "filters".....Well, they are called a "Choke Filter" and cost about $8 bux each......Garman suggested putting one on the GPS pos. lead and, if that didn't quell the static, put one on the FM and another one on the VHF. As I looked at the thing, looks like an expensive way to do what Dale suggested above with the three twists per inch.....I'm going to try Dale's approach first because I just can't believe I need the countermeasure of filters. I'll let you know if it helps.

FishFactory.....I wish - but the boat WAS in the water!

 

[goinsfishin]

I have the same electrical gremlins on my 89 Sportcabin. The previous owner was a plumber, NOT an electrician, and it shows.....I've spent quite a few hours tracing, troubleshooting and re-wiring and have come to the conclusion that this winter she gets a complete re-wire....properly!
For now I live with it and always carry my electrical trouble box and a DVM....so far my previous cleanup is working fine.

As to the radios/GPS...Where are the antenna wires running? if they are coiled together under the helm or sharing a cableway then the bleed thru between cables will exhibit exactly the issues youre having.

 

[TOPFROG]

Hey - Thanks Sandpiper.....
I'm determined to defeat this thing but I'll have to get my hands on the boat this weekend and then again when I get back to the bay 3 weeks from now. I'll let you all know what the ultimate solution is when I uncover it. Couple of things on the antenna wires.....The GPS antenna wire is isolated from both the FM radio and the VHF antenna leads. I don't honestly know if the problem existed when I bought the boat or I've done something to cause it (doubt that)....When it was surveyed, the guy said the VHF and GPS "checked out".....There was no antenna on the AM/FM as the previous owner just used it to listen to Buffett CD's :lol:

I put in a ribbon antenna and, with the GPS off, it's amazing how good the AM/FM reception is. Turn on the GPS and the reception of static is even better :!:

Thanks everyone and keep those ideas coming - We'll whip this thing or turn all of it off and navigate by feel:shock:

 

[Bryan 2530]

I put in a ribbon antenna and, with the GPS off, it's amazing how good the AM/FM reception is. Turn on the GPS and the reception of static is even better

I just got rid of the ribbon antenna that was one my boat. I could not get any local stations with that thing. Reception improved but same problem with GPS. I'll try the twisted pairs to eliminate crosstalk and see if that works to. Thanks for the heads up on the filters.

 

[DaleH]

Ribbon antennas:
No problems with mine ! It's mounted across the bottom of the port window, about 1.5" up the glass.

In-line ferrites (filters) or 'chokes':
These IMHO are an expen$ive and LAST resort (per Furuno's own manuals) ... twist your power leads and run them away from 'other' noise producing runs.

 

[TomS]

Good tip on using the tone generator to help trace wires.

Note that you can do the same thing with most digital multi-meters that support continuity testing.

Dale, whats the purpose of using "plenty of dielectric grease"?

-- Tom

 

[DaleH]

... whats the purpose of using "plenty of dielectric grease"?

Meaning enough to coat the terminals fully ... enclosed space, but in the enclosed transom, subject to humidity and vapors from water collecting in the bilge. Just added insurance ... so many don't use it or even know about it.

 

[Porkchunker]

Thanks Bryan.....In my conversation with Garman, I was told the GPS antenna transmits NOTHING....It is simply a receiver. I was also told that Radio Shack sells a noise filter (called a choker I believe). Was told to put one on the GPS positive feed - if that doesn't solve it, then also put one on each radio and that surely will "fix" the problem. I wanted to see if there was someone out there that understands what's going on so I can fix the problem "correctly".....If filters is the correct way, then I guess that's what I'll do.

All these devices are now essentially hand-held computers that run at various clock-driven frequencies. They ARE TRANSMITTERS, but not coherent ones (meaning they generate unintelligible noise). If the device is not well shielded, the VHF will pick it up. Make sure the GPS and the VHF are bonded to the same ground. If that doesn't work, then internally the GPS is not properly grounded, or the grounding plane has been compromised with a break/corrosion.

Dave

 

[TOPFROG]

Thanks PorkChunker....This was to be my weekend project before going to Bulgaria (tomorrow).....Anyway, got to my place Saturday morning and found a huge maple tree across my entrance road......VHF/FM/GPS must wait for a couple of weeks......Spent all weekend on the wrong end of a chainsaw.