Universal Engine Panel Wiring Harness Uh-oh's

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Yesterday was a beautiful day to work on the boat.
One of my projects was to remove the alternator to have it checked and to trace the Bat + wire coming off of it. It didn't appear to go to the starter as I expected.

My C30 is a 93 and I thought Catalina did away with the engine panel ammeter and wiring harness trailer plugs by then. I did pull the panel before the sea trial and saw the panel wires went into a terminal strip, then forward to the engine compartment.
No trailer plugs to worry about.

After I pulled the alternator I started to trace the orange 10 Ga wire. As I untaped and took off the plastic wire loom, I noticed a bump in the harness that was taped up. Uh-oh #1.
As I took off the tape I found it to be hard and brittle on the hump. Uh-oh #2.
When I opened up the harness it was Uh-oh #3.

Whoever removed the trailer plugs only went half way with the upgrade. Instead of running the alternator charging wire to the starter, they left it running to the engine panel then back forward.

Not sure if there is enough slack to cut out the bad sections and reconnect or if I will need to buy a new harness. One advantage to a new harness is I can install new terminal strips and use heat shrink rings instead of butt connectors.
Opinions on this?

As bad as these wires look, the motor started fine during the sea trial. I'm surprised because I thought the panel got it's power from the red wire whose connector is in the worse shape.

Good thing I enjoy electrical work.

In the photos below the orange 10 Ga is to the left of the yellow w/ red strip wire. The red 10 Ga wire is to the right of the yellow w/ red stripe wire.

Wire Conn 1.jpg Wire Conn 2.jpg Wire Conn 3.jpg
 
Oct 26, 2008
6,041
Catalina 320 Barnegat, NJ
Bundled wires are like a box of chocolates! Ya never know what you're gonna get until you open them up!
Good luck and keep your hatches closed! ;)
 
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Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
Not sure if there is enough slack to cut out the bad sections and reconnect or if I will need to buy a new harness. One advantage to a new harness is I can install new terminal strips and use heat shrink rings instead of butt connectors.
Opinions on this?
It is rare that the wires go bad, as you said, it's the connections/connectors.

The "deal" with the AO wire to starter is explained here:

OEM 1-2-B Switch Wiring History http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101

The connections are discussed in detail in a series of different posts in our Critical Upgrades topic, which you most likely have seen: Critical Upgrades http://c34.org/bbs/index.php/topic,5078.0.html
 
Jul 8, 2012
126
Catalina 28 North East
Ward - which engine do you have on the Catalina 30? My 1991 Catalina 28 has a Universal M3-20, when I rewired I found the upgraded wiring schematics #200360 helpful.
It is on page 25 of this manual -

https://www.westerbeke.com/operator's manual/200550 ed. 2 universal m3-20b through m-50b operator manual.pdf

It was not an exact match for my upgrade - (adding the glow plug solenoid, 20 amp breaker and rewiring) but it had a lot of useful information and the wire colors matched the existing harness.
I also rewired the alternator output to the house bank and added a safety cutoff as described in Mainesail's articles.
Its not too bad a project particularly if you don't mind wiring work, in the end you'll know the system inside out and all should work well with no surprises.
 
Jun 19, 2004
365
Island Packet IP 32 99 Forked River, NJ
Yeah!!! What dlochner said. We did our M3-20 harness a couple of years ago and replaced the ammeter with a voltmeter at the same time. Big difference! Batts charge faster ( even with the stock charger) and no cranking problems.
Since you're working on this anyway, why not replace the old untinned wire and lose those butt connectors too.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Ward I’ll be replacing my harness and rewriting the panel when the weather warms up. I got weatherpak connectors for the panel end and will divide into tow groups - power to the panel and power from the panel. This way I won’t have power on the male ends.

Mahalo
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Yep, I've studied every one of Maine's articles that might pertain to my C30 and that one alerted me to the trailer plug issue. Which is why I was surprised the plugs were taken out but the alt was not wired to the starter.

It is rare that the wires go bad, as you said, it's the connections/connectors.
The "deal" with the AO wire to starter is explained here:
OEM 1-2-B Switch Wiring History http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101
The connections are discussed in detail in a series of different posts in our Critical Upgrades topic, which you most likely have seen: Critical Upgrades http://c34.org/bbs/index.php/topic,5078.0.html
Yes Stu, I've studied all the critical upgrades threads on the C34 site so I knew that I had to investigate where the alt charge wire went. When I'm done with my electrical upgrade the alt Bat+ will be connected to the house bank.

As I see it I have three options.
1. Cut out the bad sections and use butt connectors, which will end up closer to the engine/heat.
2. Install terminal strip and add new wire from terminal strip to engine. I doubt I can stay with the color code that way.


3. Buy the CD wire harness so I stay with the proper color code and wire size from engine through terminal strips to engine panel.

Leaning towards #3.

Ward - which engine do you have on the Catalina 30?
I have the M-25XP. I have a few wiring diagrams but didn't think to look at the engine manual. Will do.

why not replace the old untinned wire and lose those butt connectors too.
Yep, I'm leaning that way.

will divide into tow groups - power to the panel and power from the panel
Les, I like this idea. I'll probably use it. Those weatherpak connectors look interesting.

Bundled wires are like a box of chocolates! Ya never know what you're gonna get until you open them up!
Good luck and keep your hatches closed! ;)
Cathy got a laugh out of this one.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Don’t forget option 4 get the wire and build your own harness. I have two local places I can buy all the colors I need to build the bundle. If you use relays for the glow plugs and fan - it can all be #14

Mahalo
 
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Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
Opinions on this?
You know the correct path to take. Do the work that will mean it is done correctly. This way you will relieve your mind of worrying is it going to break down just when it is critical. Done once and move on. There are many more things to occupy your mind.
If the wiring harness is your choice it is a good one. At least it is a choice for you Catalina folk. My CAL choice was total rewire, or cleanup temporary with planned total rewire. I chose the latter as it was minimal (a one day task of changing out the terminals and removing the ammeter from the circuit) work. Phase two will be a total rewire to be attacked later 2018.
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
As I see it I have three options.
1. Cut out the bad sections and use butt connectors, which will end up closer to the engine/heat.
I had the pleasure of speaking with Maine Sail on Monday. He suggested I go with this option. He said the butt connections are just fine when done properly. I am also going with his idea of replacing the inline fuse near the starter on the start button/starter wire.

Don’t forget option 4 get the wire and build your own harness. I have two local places I can buy all the colors I need to build the bundle. If you use relays for the glow plugs and fan - it can all be #14
Les, I found all the wire colors and correct Ga at genuinedealz.com in 25' lengths. Costs would be about $60 less than the CD harness. If I decide to change out the harness, that is the way I will go.

Part of this repair will include adding the glow plug solenoid and another inline fuse on the red wire at the starter that feeds the panel.

I am already planning on running the alternator Bat + directly to the house bank.

What I won't do is tape up the bundle of butt connectors nice and tight, then put them in wire loom so they are well insulated. I believe that will trap any heat from any resistance in the connections. If done correctly with adhesive heat shrink connectors they should be fine in the open.

Thanks Everyone.
 
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May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Sounds like a good plan. Surprising how many boats still have the trailer plugs. Mine came with one up by the panel. Changing the solenoid fuse is a great idea, that one bit me whil out cruising with my son.

The other must do that wasn’t on my boat was the M25 alternator bracket upgrade, even with the old bracket breaking off a chunk of the timing cover the P.O. fixed the cover but not the bracket.

Keep up the good work & good luck

Mahalo