Off season electrical re-wire

[Indy]

I have a late model A4 and have decided it's time to overhaul the electric. Most of the wiring from the engine appears to be original, all of which leads to a terminal block. The block is suspended above the engine, hanging from what appears to be at least 10 feet of wires - all correct color coding and neatly wrapped in a loop that is tacked to the engine compartment ceiling. That loop of excess wires terminates in a trailer type plug that leads to the gauge panel. It's quite a mess and seems like a very likely, eventual point of failure that will be difficult to diagnose if there is a problem.

I plan to do the following and would appreciate words of advice. There is nothing complicated about this, but I'm just somewhat experienced in re-wiring systems on this boat.

1) Remove the trailer plug and permanently mount the terminal block to the engine compartment wall. I've added a couple photos, one of the terminal block, the other of the plug. I don't have a good picture of the wire loop, but it appears to be pristine wire, almost still looped the way it was whenever it was installed.

2) Use the existing excess wire that is tacked to the ceiling to wire from engine components to the block.

3) Use existing excess wire to complete connections directly from the terminal block to the gauges.

4) Replace all the gauges and potentially the ignition & fan switches.

5) Clean all connections.

[Dave Neptune]

Great idea!! The "trailer plug" is the subject of many electrical trouble shooting threads and problems on this site. Another is to get away from the ammeter and go to a volt meter in the cockpit as the back and forth runs just costs power. If you still want an ammeter get one that uses a shunt so it can be mounted close to the output and the gage can be mounted anywhere you wish. I also suggest if you are going to use the existing wire that you shorten as much as you can and replace any of the wire that shows "black wire" corrosion.

Do mount the connection block somewhere solid and coat the block and wires with dielectric silicone or equivalent to seal them from moisture.

Sticking with the color coding of the stock engine is nice for trouble shooting but not absolutely necessary especially if you make a drawing or tag the wires as to what they are.

Dave Neptune

[ndutton]

Here is my Cliff Notes version of general considerations posted 10 years ago:

https://www.moyermarineforum.com/for...5&postcount=16 and repeated here

(In direct response to another member's question on grounds)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 (ground) 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.

edit:
Here are before and after pictures of forum member Ezra Korts CAL 29. The engine rewiring took two of us a single day including sourcing the wire at the local chandler (San Diego) and a very nice lunch.