I did it again

[gwwannabe]

Once again I did not do a thorough enough job of troubleshooting a problem. The stereo system quit working last fall and after some cursory checking, found I had 12+ volts to some device wired in line before the unit but not after it. I decided to replace it the system.

I went to install the new one yesterday and finally came upon the real problem. The accessory fuse block under the helm that the stereo is wired into apparently has some corrosion problems. As soon as I try to turn the stereo on, the line voltage drops well below the 11 volts required for it to run. Volt meter without load shows 12.7 volts. Ran out of daylight yesterday so will pull the fuse block out today to clean it or possibly replace it.

Only saving grace is that the old stereo didn't work very well and the new speakers will sound much better.

Gary 89 Overnighter

 

[seabob4]

Check the condition of the feed that powers that fuse block. Should be 10 GA and you'll probably see it's black...

 

[bc282]

yup, i have similar issues with console fuse block.
I'm beginning the process of running a pair of good tinned copper 4 gauge wire to be the new main lines for the new blue sea fuse block. Also replacing some of the wires feeding accessories with tinned marine wire and proper marine grade connectors.
I know 4 ga is overkill, but i'm getting it for a good price so for a few bucks extra i think it's worth it.
The orginal 10 gauge IMO is too light and as i've added to the demand, i feel i need a heavier wire to safely handle the amperage draws.

IMO and many will agree, the Grady wiring is not great. A little too much use of non-tinned wire, automotive grade connectors on the wires that allow for corrosion. Over time and exposure problems begin to occur such as the one you are having now in which corrosion is creating too much resistance; so it's like trying to feed an elephant with a straw--ain't gonna happen.
small stuff like lights may continue to work, but items that demand a decent amount of juice will not work.

I'd bite the bullet and take the time to replace as much of the wires as possible as the "sub-par" stuff will only eventually give you grief and perhaps in critical times too.

 

[gwwannabe]

I pulled each of the fuses out of the block yesterday and found both ends covered with a dirty, greasy substance. I'm guessing it's dialectic grease. I cleaned it off and used emory clothe to clean each of the fuse holders and connections. Every thing is working well now. I want to pick up some more dialectic grease - it really works well anywhere dampness/moisture is present. By the way, do any of you use that liquid electrical tape?

It's such a rats nest under there, nothing labeled, and a number of in-line fuses for heaven-knows-what. That'll be a good rainy day project - figuring out what each is for.

Gary 89 Overnighter

 

[seabob4]

The biggest problem with older boats, even with all tinned wiring, is corrosion in the wires, the dreaded "black" wire. It just makes everything work harder due to decreased voltage and increased heat, and really does shorten the life of all your equipment. But a total rewire can be a very daunting (and at times an expensive) task. Just something to think about...

I'm sure GW used marine color coding in their harnesses, this will help you identify some circuits:

Brown- Bilge Pump Switched
Brown/Red- Float Switch Constant Hot
Brown w/stripes- Livewell, washdown, Fresh Water Pumps
Blue or Blue w/stripes- Cockpit, courtesy, cabin, dome, spreader lights
Gray or Gray w/stripes- Nav, Anchor lights
Green- Bonding wires
Yellow- Stereo Memory, Bilge Blowers
Red- 12V+ feeds
Orange- Horn

Hope this helps with the ID. And yes, I use Liquid Electrical Tape (Liquid Neoprene) on the studs of battery switches and on positive and negative bus bars.

 

[gwwannabe]

Thanks, Seabob, that should help. Seeing the color chart reminded me of the problem I had when I connected up the speaker wires Friday. I'm color blind and couldn't tell which wires were green and which were gray. The wires were obviously different colors but I didn't knhow which was which. I ended up with speakers on left front and right rear. Had to have a neighbor come over and id the wires. After 63 years it can still be embarassing.

I installed the speakers that came with the new unit today. I was originally thinking I'd just replace the old speakers but they sounded pretty good so I added the new ones. Wasn't a bad job once I decided where to put them. I really like the sound the system produces now. However, if I crank it up the old speakers start breaking up so they'll get replaced before long.

This system calls for a direct connection to a battery to maintain the memory. After playing with it all afternoon, I think I'll run a wire back to the battery, add a fuse, and keep the memory active. It was a pain to go in and reset everything each time I switched the batteries off. Anyone think this is a bad idea? The bilge pump is the only thing always connected to power now.

Gary 89 Overnighter

 

[seabob4]

Gary,
Yes, the yellow wire off the stereo needs to be "constant hot" to maintain stations and settings. Here's how I drew up the typical bilge wiring for a single engine/dual battery boat, note the yellow wire coming off the batt switch...

That is the stereo memory lead.

 

[richie rich]

GW...I use contact grease on my connections.....not dielectric grease....the dielectric grease acts as an insulator...it was used in the old days on spark plug wire boots and points in a distributor as a lubricant that did not transmit electricity....the contact grease protects you from the environment, but allows good conductivity between the metal parts in contact with each other....hence thats why they use it for OEM computer and electronics connectors....just my HO....BOB C...whats your take as a pro on this area?

 

[gwwannabe]

Thanks again, Seabob. The unit I bought is manufactured by Dual and the wiring diagram has yellow going to a keyed source and red being the memory wire going to an always hot source.

Richie, the contact grease is what I want. Around motorhomes, dialectic grease is often promoted as doing the same thing. I've often wondered about that and assumed that it works by keeping moisture and air away from the connection. Seems like contact grease would work the same way.

Gary 89 Overnighter