Rewiring a 17' bowrider o/b -1977, ??s

I'm just now learning about electronics and see this as a challenge. I'm looking at the minimum gauges/appliances - lights, horn, and a new bilge pump (draws 5 amps/10amp fuse). The dash has a Tach, Speedometer, Fuel, and a hole for one more gauge (maybe was a trim indicator). The instruments are all wired in at present. The wires are a mess at the stern although up front looks reasonable.

Looking at buying a bus bar that could have fuses inbuilt and will check whatever else is out there for circuit breakers. Currently, there is some kind of a buss bar up front but judging from the year, new is probably better. The previous owner told me that all the instruments had been working.

What size of fuse would be best for the bus bar in a boat this size - or is it all circuit breakers now? Or is this even needed. I'm trying to not get a whole bunch of wires going to and from the battery.

The motor is a 1990 90hp Merc and has the wiring set up for a tach and a small 6" rubber tube sticking out from the leg (must be for the speedometer?- so may as well use them).

The battery is located about 12' from the dash so what gauge of wire would be the best to run from +ve buss to positive battery and from -ve bus to negative battery. I think I have used 12 but perhaps this might be light?

The bilge will be hooked up from the existing switch via the bus bar and fused with a 10 Amp inline. What gauge wire should I use for this (it draws 5.6 amps).

What gauge(s) are generally used for the other instruments?

Information/thoughts on the above will be greatly appreciated and I will continue my readings

Re: Rewiring a 17' bowrider o/b -1977, ??s

Went to Bass Pro today and I think I have the hardware to solve my wiring situation.

For $40, bought a 6 gang fuse panel (they also had a 4 gang for $30) with 6 x 7 amp fuses and max of 35 amps - one under the other and each has its own circuit breaker also arranged vertically beside them. It takes glass 7 amp fuses. On the right hand side is a place for the names of the appliances connected with 24 preprinted sticky labels to change the labels already in place.

The entire unit is 4 1/2" by 6 1/2" and predrilled on the corners for mounting. No more bus bar (but can be optional), no more separate cb panel/fuses.

I will use a primary 12 ga wire from the +ve battery to the fuse bar and another 12 ga wire from -ve battery to the cb bar. Each cb has 2 short, tinned wires for connecting to the appliance. The instructions are on the box.

This should work very well for a typical type of run-about. We shall see.

Re: Rewiring a 17' bowrider o/b -1977, ??s

While the fuse panel directions said a bus bar was optional, I found it to be a necessity so bought a five point/2 terminal Sea Breeze bus bar for $18.

For those who need a simple wiring and are overwhelmed by schematic diagrams, I'm stretching out what worked for me.

The panel has a set of fuses on the left connected with a positive wire (marked) . This +ve wire was connected directly to the primary positive wire from the battery.

In the middle of the fuse panel there are 6 pigtails (for each circuit) to the left side of the circuit breakers and these are all +ve. On the right side of the circuit breakers is the -ve line with a 4" extension (marked).

This -ve 4" extension is connected to one terminal of the bus bar. The -ve primary wire was connected to the other terminal on the bus bar - so the bus bar is -ve with five screw in terminals usable.

Bilge:
I ran two wires for the bilge to the front.
One went to the -ve part of the switch
One went to a -ve terminal on the bus bar
The Bilge pigtail (+ve) was connected to the center (hot) part of the switch.

Horn
One wire to negative part of the switch
One wire to a bus bar terminal
Wire from horn pigtail to the center (hot) part of switch

Stern Light (Anchor light)
This had been pre wired at the back of the boat with one wire going forward. This wire went to the bus bar.
Wire from Anchor Light pig tail to center (hot) part of light switch

Bow Light
One wire to bus bar terminal
One wire to negative part of the switch
Wire from Running Light pig tail to center (hot) part of switch.

I like the idea of having the Nav Light on a separate circuit breaker than the Anchor light. This way both can be put on for running and the Anchor only when stationary.

They all work, and I now know how things are wired up.

Thanks so much for all the help from moderators/contributors
on Iboats. It is wonderful that so many are eager to share their thoughts/experiences to help others out as they work though problems with their boat.

One of the best tips was to draw out your plan on paper and this worked great. A second tip would be to use a good set of cutting, crimping, stripping pliers - the cheap ones just don't cut it for those male/female ends

Hopefully this will be of help to someone working on wiring.

Steering is done (new telelex helm), electrics are done, fuel tank has been drained. All that is left is to hook up the controls to the motor, put in some gas/oil and fire it up. With an luck, I may even be able to wire up the Tach as all the hardware seems to be there.