Grasshopper learns from the Master

Nov 22, 2008
3,562
Endeavour 32 Portland, Maine
Or: Why it pays to get someone who really knows what they are doing.

Readers of my forum section know that I didn’t have radar after my mast went up. Even though I had led all the wires out side the mast access plate, intending to clean and overhaul everything and put it together myself, the yard rigger went ahead and plugged everything in and taped it. (Note to self: Leave a note next time.)

I took the radar power connector at the base of the mast apart, verified 12 volts, and gave it a quick scrape to see if a bit of an oxide layer was the problem. Nada. I took the plugs off the wires and checked the screws. Still no radar. Very high resistance across the wires going up to the radome, almost an open circuit.

I accepted Maine Sail’s offer to go up the mast. He showed up, looked first at the deck connector, sprayed the pins with something called DeOxit D5, put a small screw driver in the split brass pin and spread it a bit. He plugged it back together and the radar fired right up when we turned it on. No trip up the mast.

Here’s what I learned. Brass can look quite clean and still have a high resistance oxide layer. My quick scrapes were below the surface of that so didn’t allow contact. Brass also doesn’t hold its spring very well so my quick and dirty “diagnostic” scraping just pushed the split pins further together. The connector felt tight but that was probably only one pin. The Garmin radome doesn’t turn on, and thus shows open circuit across the power wires, until it gets a signal from the chartplotter via the separate network cable.

What’s interesting is to think about how this could have gone. I was sure the deck connector was OK. If Maine Sail hadn’t come, I would have sent the yard guys up the mast to fiddle with the connector on the radar. That couple hundred dollars wouldn’t have fixed things. So, I would have sent them up again to bring the radar antenna down. It then would have gone off to Garmin while I fumed and wrote checks to the yard. Garmin wouldn’t have found any problems. I would have posted some nasty things about Garmin. I’m not sure where the story goes from there but a hot bath, sedatives, and razor blades come to mind.

Another take home lesson is to calm down and be methodical. It’s easy to get frantic when a big problem like this crops up and it’s hard to think sitting in hot sun. Perhaps this is why doctors always have another physician treat family members. Since I had the wires out of the connector anyway, I could have verified 12 volts on the sockets with the connector mated. That would have revealed the problem and saved me the modest but invaluable cost of Maine Sail’s time.

But, hey, if I was perfect, think what we all would have missed learning.
 
Feb 26, 2004
23,037
Catalina 34 224 Maple Bay, BC, Canada
Great news, Roger. At the risk of tongue-in-cheek repeating what MS says a lot of the time: "If it's electrical --- Check the connections.!" This one gets into "the next level."

Hope Barbara's boat gets fixed and you can start your cruise.
 

WayneH

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Jan 22, 2008
1,093
Tartan 37 287 Pensacola, FL
OH, Damm. That sounds familiar. I had a 12V plug that wasn't working on the boat. Volt meter reads 13.8 volts but nothing WORKS in the plug. I'm hot and frustrated and every now and then the damm thing starts working.

So, I've checked the wiring at the plug for like the 5th time and I'm absolutely certain that the plug should work. And it doesn't. And I'm sweating bullets because the fan I'm trying to get running goes into this plug. I've tried it in another plug and it works but it just won't run in this plug. And the volt meter reads 13.8V. AAARRRRRRRGGGGGHHHHHHH!!!!!!!!!

I finally decide to trace out the wiring because I'm not sure how the DPO ran the wiring to this plug except that it is tied into the cabin lighting. You know how wire tracing goes. Uncomfortable positions with contortionist arm twisting to feel the wire coming out of the plug and headed to the breaker panel. Well, about a foot from the plug, the wire enters one of those blue stab connectors. (I hate them and I haven't eliminated all of them yet.) Feeling around on this connector to get to the other end of it, I moved it just a little bit and the freaking fan comes on. A slight twist back and the fan goes off. I've now got the plug hot all the time but I'm faced with the problem of removing this little piece of garbage and replacing it with something that won't fail while being unable to see whatever it is that I need to do.

I think I need to take a bunch of pictures of what's in there so I can make a good decision on how to undo the damage while blindfolded. LOL
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Roger,

Glad I could help and glad you did not need to hoist my fat arse up the spar.. Those two pin plugs are one of the most unreliable things I run across. As you saw they often look fine but won't pass current. The problem is with the un-tinned brass. Whenever buying plugs for the marine environment try and find ones that are tin plated. The tin plating resists corrosion much better than bare brass. Also the male "split pins" have a terrible knack for losing their outward pressure..

This is the type of plug Roger had trouble with:

Photo Courtesy Wholesale Marine

 
Nov 22, 2008
3,562
Endeavour 32 Portland, Maine
Those two pin plugs are one of the most unreliable things I run across.
The weird thing is that I have the same plug on the transducer for my knotlog so I can remove it for cleaning the critters off the paddlewheel. It gets sprayed with salt water every time I pull the unit. The pins look like an old penny you find in the bilge but the knotlog has never stopped working. I checked it after you left and the knotlog was working even though the plug looked 100 times worse than the radar plug. Gave it your full treatment and put it back together.

You can't go by appearances on these things. The knotlog plug is one of the things that had me fooled.