Rewire engine ( warning long post )

[ndutton]

Technically you can have as many ground wires on the engine as you want. I'm trying to nudge you in a direction with the bus bar of a professional looking and superior installation. Train the wires neat, clean and parallel, support the wires independent of their termination, run them as far as you can inside the split loom and have them exit right where they terminate. Looks good = IS good.

My top 10 list of hints:

1. Take your time.
2. Make the harness on a bench. Only one wire per color allowed.
3. No splices allowed mid wire. If a wire is too short, replace it with one of sufficient length.
4. Speaking of sufficient length, 'tis far better to throw 2 feet of wire away than to be an inch short. Don't skimp.
5. Place the harness in the boat and fasten it to the structure.
6. Connect the ends where they go.
7. Train the wires away from heat sources, sharp edges and moving parts.
8. Make notes on your diagram for future reference.
9. Sit back and bask in the glory of a job well done.
10. Take pictures before and after for our admiration.

[seapadrik]

Thanks for the tips. I cant wait to get to the boat in the morning and begin addressing some of this stuff.

But first more questions.

Its clear in looking at some of my photos that they basically had the "starter hot" and bilge switch hot basically sharing a ride ( via a fuse block near the instrument panel ) to the Battery. They used the ancor duplex wire to make the run to the battery specifically.

Now to my question looking at the diagram.

Are you suggesting to take the starter hot #12 directly to the battery ? Also, I bought the 20 amp fuse today. If i am to take that directly to the battery should the fuse be near the instrument panel or near the battery ? Same for Bilge blower switch, Should I take its hot wire directly to the battery ?

Or if i look closely at the diagram again, it appears that the starter hot red wire #12 begins at "B" position on ignition switch and terminates on the alternator ? is that correct ?

Also regarding the black #12 wire in your diagram. What specifically does that attach to at the instrument panel ? and where does it terminate ?

Sorry to ask so many questions. its just in my mind i am trying to reconcile the diagram you made for me, plus what they had at the boat, and the Moyer diagram. And its not yet clear.

thanks

[ndutton]

You may get other opinions but here are mine:

1. Best practice is to treat the battery connections the same as we discussed with the engine grounds. Battery cables only at the batteries and as few of them as possible. See battery wiring diagram as a conceptual example. I'm not suggesting this will work for your boat because the diagram has 5 batteries and 2 switches but it's an example of battery wiring practices.
   E-1 Battery Wiring.pdf
2. Negative from the battery goes to the engine block. Positive from each battery goes to a battery switch (terminal 1 or 2) and from the battery switch (terminal 'C' for common) to the starter post.
3. Appliance grounds come from the ground bus, hots come from their respective circuit breakers on a distribution panel. It's best to keep the engine electrical separate from the boat electrical.
4. The black (ground) wire in the engine harness attaches to any instrument or device on the instrument panel that requires it. Examples are the voltmeter, gauge illumination lamps, tachometer. The oil pressure, water temperature and fuel gauges get their grounds via their respective senders.
5. The voltage path on the red wire begins at the starter post (the same post as the battery cable from the battery switch common) and ends at the keyswitch 'B' (for Battery) terminal.

Dig through Calder's book. It will help clear the fog. And don't worry about asking questions. Somebody answered my questions a long time ago, now it's my turn to pay it forward. No problem. While all this may seem daunting, really it's one wire at a time.

[seapadrik]

Alright,

I was able to make some progress today, but as always never as much as I like.

Here is the harness being constructed on my boat.

http://www.flickr.com/photos/28554500@N08/9113155132/

All wires were the exact colors, except for 2. I had to use "brown" instead of tan for water sender. And i had to use dark blue instead of "brown w/yellow" for bilge blower. It is what it is, i just didn't want to use "reserved" colors like red, purple, black, yellow in the wrong places.

As it turns out I had to stop because I have to drill slightly larger holes to accommodate this engine harness, and didn't have the proper bits on-site.

I have decided to install a #6 to the rear of engine some where near water pump and connect that to a BUS on the bulkhead just across from the alternator. I will run anything that needs to be grounded to this bus bar.

http://www.flickr.com/photos/28554500@N08/9113152786/

Tomorrow i will install all of this. I have a question about the connections for ground back at the instrument panel.

what is the technique for daisy chaining all those grounds ( voltemeter, temperature, oil pressure, etc..) together ?

I will have one 12 gauge wire ( I bought yellow instead of black ) at that point available to me. How do i connect those together ? Would it be another small ground bus at the instrument panel ? OR do you guys pigtail these like they sometimes do in AC wiring ? Although if one does a pigtail i am not sure what connector would bring two wires together. At this point I may as well connect things correctly.

Thanks

[ndutton]

what is the technique for daisy chaining all those grounds ( voltmeter, temperature, oil pressure, etc..) together ?

A separate ground bus is not typical at the instrument panel (there's nothing wrong with a bus, just not typical) so the question is how to daisy chain? Either make short jumpers with ring connectors on the ends or put two wire ends in a single ring connector and crimp them together.

Without getting into the doomsday stories of not using the proper ratcheting crimping tool (preached by the same entity that coincidentally happens to sell the tool) be sure to test each finished crimp by trying to pull it apart.

Caution: See edit below
Not all gauges require grounds for their operation (some do, some don't). My oil pressure, water temperature and fuel gauges do not, hot and sender wires only. Illumination lamps in the gauge require a ground but note it has nothing to do with the function of the gauge, only the light bulb.

Looking good by the way.

Edit:
That paragraph is totally wrong. Subsequent testing and comparing readings of new gauges to old embarrassed me that the ground is absolutely necessary for the gauges to read properly. Sorry for the inaccuracy and I hope this corrects the information.

[seapadrik]

Update Sunday evening:

A little bit of progress was made here. As you can see I got the harness installed. This is the view from the engine above. I am still not done and will post more pics as I get closer. Still have to wire up individual devices.

http://www.flickr.com/photos/28554500@N08/9121316481/sizes/l/in/photostream/

You are right. It is nice to have it all in one spot.

Now for a couple of questions. When I was examining all this today I decided to follow all 3 #4 GA hot wires from both batteries and the Alternator to the Perko switch to inspect wire condition. What I expected when I got to the Perko switch was to find the following:
#1 on switch > #1 battery
# common post on Perko switch to Alternator
# 2 on switch to house #2 battery

What I found was close in that #1 was correct. However it appears the common post was connected to #2 battery instead of alternator. So it was as follows:
#1 on switch > #1 battery
# common post on Perko switch to #2 house battery
# 2 on switch to Alternator

Is there any reason the PO would have done that ? I just assumed standard was to do common post to Alternator ? If my understanding is correct with this set up I would only have gotten a charge to the batteries via "both". I also could have charged battery #2 if I was on that setting. #1 would have never been charged from the alternator, except for the both setting.

I probably didn't notice since I have those Guest battery chargers at the dock attaching to both batteries directly. Can I assume that I should reverse this so that the common goes to the ALternator ?

I have another question. Can anyone describe this thing ? It is installed on the outside of my fiberglass battery box and had a gray wire attached to it

http://www.flickr.com/photos/28554500@N08/9123536770/in/photostream/

http://www.flickr.com/photos/28554500@N08/9123535560/in/photostream/

I have no clue. Maybe these wires are so delicate it needs that little box to connect to the battery ?

More to come this week. Looking forward to your responses and as usual this forum rocks.

Thanks

[ndutton]

Your understanding of battery selector switch wiring is spot on. The P.O. or whoever he hired to wire it up reversed battery 2 and common.

The mystery part looks to me like the sensor for a Xintex gasoline fume detection system.

[ndutton]

Consider pulling the purple ignition wire out of the split loom close to the coil, same with the red hot and white starter wires close to the starter. This is not an electrical suggestion but rather one of style.

[toddster]

Nice looking engine compartment. And I might just copy that cut-out to get better carb access. I've got an engine wiring refresh coming up soon too. I've been toying with the idea of leading the wiring harness to a fuse/breaker block at the engine end, and running short wires from the engine to said block. Also mounting a main grounding buss in there somewhere. Thoughts?

[seapadrik]

Neil,

When I go to wire up individual connections at the engine compartment, I will definitely have it leave the harness ant the appropriate point. I just wanted to be over the top and make sure I had plenty of wire before doing that.

I will make sure the common pole on Perko switch goes to engine compartment instead of battery #2.

Toddster, thanks. That cut-out was done be the previous owner and I couldn't imagine that spot being a solid bulkhead. Its tough enough as is.

Thanks

[ndutton]

Great Patrick. It's looking really good. What a huge improvement.

Todd,
As a matter of safety and USCG compliance, if you're thinking of a fuse/breaker panel inside the engine compartment it needs to be ignition proof in case there are fuel vapors present. I'm not sure ignition proof breakers even exist and if they do, hold on to your wallet.

[toddster]

Great Patrick. It's looking really good. What a huge improvement.

Todd,
As a matter of safety and USCG compliance, if you're thinking of a fuse/breaker panel inside the engine compartment it needs to be ignition proof in case there are fuel vapors present. I'm not sure ignition proof breakers even exist and if they do, hold on to your wallet.

Yes, but blue sea has a panel that takes automotive blade-type fuses. Just as an alternative to a bunch of separate in-line fuses. In my case, it would probably be on the side of the galley just above the engine compartment, but that could continue a current problem of having most of the wires and hoses crossing over the engine. I like the layout shown in Patrick's picture.

[seapadrik]

Neil,

I had another question regarding the diagram you made for me as I try and finish this up this week.

1. What you are describing as field wire ( looks to be tan or brown by the diagram ). If I am reading that correctly that will go from my Excitor on my 55 amp alternator to positive of coil. Is 14 gauge sufficient ?

2. Regarding the coil > oil safety switch > electric fuel pump wiring. I plan on using 14 gauge purple for those connections, ok ?

3. I will do a 14 gauge yellow from fuel pump mounting bracket to ground bus bar on engine wall

5. I will do a 14 gauge yellow from blower motor to ground bus bar on engine wall

6. The PO only had the starting battery grounded to the engine. Should I ground all battery negatives together, than have one longer ground going to the engine ?

Thanks

[systemek]

Clean!

This is looking GREAT!

[ndutton]

Patrick,
Questions one through six omitting four = YES!!
Look at you, you're all over this stuff.