Wiring, request for help with.

Wahoo! · 08 January 2012, 20:53

Hi everyone.
I have been doing several jobs on my Rib in preparation for spring. I bought her in September as a bit of a project. Some of the electronics are not working and the wiring inside the console is a birds nest of dodgy wiring.
I intend a complete rewire. Partly to tidy it all up and get everything working as it should, but also for peace of mind. Would anyone here be able to guide me through this task? Perhaps with a specific wiring diagram?

The electrical equipment list is as follows...

Rev counter gauge.
Temperature gauge for outboard.
Trim gauge (none of the gauges are currently wired for illumination but should be).
Compass (has a thin wire coiled up but not connected, presumably illumination?)
VHF radio, in dash.
12v power socket
Nav lights
Flood light
Fishfinder
Chart Plotter
Three switch panel marked:- Instruments, Nav. lights and on/off
6 way fuse board
Battery isolator switch.

Any help would be greatly appreciated.

Thanks in advance

jyasaki · 09 January 2012, 06:52

Rev counter, trim gauge, and Temp will all get their feed from the engine; not familiar with Merc harnesses, so I can't help there. Illum for gauges usually get wired up to same circuit as sidelights.

The compass wires are for a light; should be wired up to the same circuit as the nav lights (you shouldn't need to look at compass when sitting on the hook.)

I assume you want all your electronics on the same circuit, so they'd go back to the single switch (VHF/FF/chartplotter, and probably floodlight, assuming it has a separate on/off switch.) Make sure you fuse that circuit appropriately, or run each device through a separate appropriately sized fuse.

As to exactly how to wire up your system, it depends on a lot of factors: room for bussbars, proximity to battery(ies), etc. Sounds to me like you're going to be a little short on switches, though (that might just be me, though; I've got an 8 switch/fuse panel on my console.)

jky

MI3GTO · 09 January 2012, 19:43

Don't run more than one system off one fuse, lose the fuse you lose the lot. Send me your email and I will talk to you further. George.

Nos4r2 · 09 January 2012, 20:09

Quote:

Originally Posted by MI3GTO

Don't run more than one system off one fuse, lose the fuse you lose the lot. Send me your email and I will talk to you further. George.

Seconded.

If you run any lighting from your electronics fuses a blown bulb can short and take the fuse out quite easily.

Wahoo! · 09 January 2012, 21:16

Thanks for your responses so far guys, already some very useful info.
I've done a bit of 12v DC electrics on cars in the past and have decent DIY skills so think I can do this with some help and guidance along the way. Most of the kit including the 6 way fuse box is in the centre jockey console. I guess there is room inside for anything else thats required. My email address is ivorm@talktalk.net and I can send photos if that would help at all? To simplify things I intend running just one battery but will carry a spare inside the console and jump leads just in case the main one dies.
Thanks again for the help

Nos4r2 · 09 January 2012, 21:24

A good tip is make sure you can access everything easily once you've got it back together so you don't have to dismantle half the boat to change a wire etc-and make sure the fusebox is easily accessable.

If you can hand start the motor with a cord round the flywheel (try it-it's not that hard on a carbed motor), you really don't need a 2nd battery. If you really feel the need for one, it'd be easier to use a jump pack.

captnjack · 09 January 2012, 21:27

Why the spare battery? That's alot of weight for a part which generally is not the reason you're stuck at sea (bad fuel is the #1 reason)

Dr Doof · 09 January 2012, 21:28

Power Monkey.. small, easy to use and easy to carry.

Wahoo! · 09 January 2012, 21:44

Quote:

Originally Posted by captnjack

Why the spare battery? That's alot of weight for a part which generally is not the reason you're stuck at sea (bad fuel is the #1 reason)

I'm probably a bit twitchy because a flat battery cost me £130 last August bank holiday (to be 'rescued')

Maybe a voltmeter would be an idea? at least it would help me monitor battery condition and give me peace of mind

captnjack · 09 January 2012, 23:44

Why not pull start your engine? 90hp is do-able

Cookee · 10 January 2012, 07:46

Use marine grade cable and the glue and heatshrink connectors and it will last, anything you find that has blackened copper cable has to go - best policy is cut out everything and start from scratch if you have the time and the budget.

treerat · 10 January 2012, 08:17

I put a 4 way switch unit into the consol. This was then a simple two wire back to the battery via the dead switch.

Then it was fairly easy to wire each thing, VHF, echo sounder, lights and pump, to each of the live connections on the switch unit and a common earth.

Each has a fuse and worst case is I can sacrifice one thing should the fuse go in another. If you have more than 4 items, use a bigger, or two smaller, swith units.

9D280 · 10 January 2012, 12:38

I'll pretty much echo what everyone is saying about a separate fuse for each toy. As jyaski says, the engine stuff wil lbe fed direct form the engine harness. Google Image "Merc wiring diagram" and have a dig around what you find - that will take care of the engine related stuff.

I have also put a switch per toy as well, simply in case I have to isolate one for some reason (fault finding at sea kind of thing ) . There is an argument for a separate gauge illumination switch as you may find on a partuicualrly black night your night vision is trashed by the glowing tacho under your nose.....

Also check your main battery cables - I found after a rather reluctant start last month that I had a nice console heater in the form of the jump wire between the batt +ve and the main isolator. Chopepd it and it was very black inside..... 35 sqmm welding cable makes remarkably good replacement.

Only other high level suggestion I would make is to take a length of wood, and park it across your toobs. Try if at all possible to fit everything above this level. Simply because if you ever get swamped, the whole lot will die of corrosion in a matter of hours or days. Not of course that I speak from experience on this matter.....

rigi36 · 10 January 2012, 15:07

Quote:

Originally Posted by 9D280

Also check your main battery cables - I found after a rather reluctant start last month that I had a nice console heater in the form of the jump wire between the batt +ve and the main isolator. Chopepd it and it was very black inside..... 35 sqmm welding cable makes remarkably good replacement.

What was it before?

Wahoo! · 10 January 2012, 19:16

Thanks again for all the useful suggestions guys. Definitely agree that individual fuses make complete sense as does seperating the lights from everything else.

I have a very kind chap on the Forum helping me by email now, he is going to draw a schematic for me so I hope to be able to make a start on it this coming weekend.
I don't have height in the console to get everything above tube height however I could place an auto bilge pump inside the console just in case of a flood but the hatches are both of the sealed type so I assume these are fairly watertight?

Thanks again

9D280 · 11 January 2012, 08:52

Quote:

Originally Posted by maxhar

What was it before?

looks like it was a bit of standard car battery cable without the waterproofing mods. The whole run back to the engine was that too, when I removed it & did an investigative removal of the insuilatio nthe black stuff had worked its way down the entire 4.5m of the cable. Granted it did look like it had bee nthere since the boat was first fitted out in 1983!

The only reason I didn't do the jumper at the same time as the main cable is that I ran out of big terminals!

Nightfisher · 25 March 2012, 14:37

Quote:

Originally Posted by Wahoo!

I'm probably a bit twitchy because a flat battery cost me £130 last August bank holiday (to be 'rescued')

Maybe a voltmeter would be an idea? at least it would help me monitor battery condition and give me peace of mind

Minn Kota makes a cheap simple to use 12 volt battery charge condition meter. Requires no power of it's own and gives precise voltage level, as well as LED 1/4 increment lights. 20.00 CDN.