Losing Sleep -- Calling in the Big Guns

[spacemanpete]

Alright, if all goes as planned, there's a wiring diagram below for a Volvo-Penta AQ80. I'm not very electrically-inclined, so I'm having trouble wrapping my head around some things I know you folks can help me with:<br /><br />A) I'm assuming wire 1 (on the left side of the terminal board) is the main hot, and the #2, next to it is the main ground -- is this correct?<br /><br />B) wire #4 connects to the coil; on the other side of the terminal board, it splits off into three wires -- one to temp. gauge, one to tach, and one to ignition lock switch. What is going on here? Electricity is flowing, when the switch is flipped, from the switch -- but then does it go to the tach, temp gauge and through the term board to the coil?<br /><br />C)As you can see, the engine has a generator. How is the energy it is creating getting back to the battery? Through which wires? Please explain what the energy in the two wires connecting to the generator are doing.<br /><br />D)Lastly I want to change the ignition lock/button to an igition switch. If I do this, wire #1 would go on battery, but which ones would go on "I" and which on "S"?<br /><br />Lots of questions -- thanks for your help -- I can only stare at this thing for so long . . .<br />

 

[kesso]

Re: Losing Sleep -- Calling in the Big Guns

Heres my take on the situation, its bloody hard to see the detail of that schematic; however, here it goes.<br /><br />A) Wire 1 is 12V (hot). Wire 2 is 12V (switched). I'm guessing 12V (switched) energises a relay to pass 12V (hot) directly to the starter motor; because, the user would not want a large current draw passing through a toggle switch.<br /><br />B) When 'key' switched to 'on', applies power (12V) to certain instruments (otherwise they would flatten the battery) and to the coil.<br /><br />c) Comes out of the Generator onto a terminal post on the starter and feeds back to the battery for charging...i think! Looks like the battery charging lamp receives switched 12V and when generator is not functioning correctly, the generator then provides a circuit/ground for the lamp to light.<br /><br />d) I know what you want to accomplish; however, unsure of what you mean with 'I', 'S' and so forth.<br /><br />Or, just rattle the voodoo cup and spread out the chicken bones and see what they tell you.

 

[Dunaruna]

Re: Losing Sleep -- Calling in the Big Guns

Terminal 1 is main ignition hot. Terminal 2 is the ignition hot for the starter solenoid - crank. (the picture doesn't show a relay but there could be one). Terminal 4 is the ignition hot for the coil/temp gauge and tachometer - run. <br /><br />The generator output is the wire connecting to the starter motor, the same terminal that the battery connects to. <br /><br />To fit an ignition switch - #1 to 'B', #4 & 3 to 'I' and #2 to 'S'.<br /><br />Aldo

 

[spacemanpete]

Re: Losing Sleep -- Calling in the Big Guns

Once again the Aussies come through. Thanks for the info.<br /><br />Dunaruna, the manual says the generator has a built in relay, but says nothing about the starter.<br /><br />The old owner has an ampere meter hooked up, not sure where -- think he replaced the charging control lamp -- can I put this "before" the ignition switch?<br /><br />Also, "XV" is the only fuse on this -- is this okay? <br /><br />I have a ignition switch with an accessory setting, but I'm thinking that this isn't best practice to run accessories off of an older system like this because 1)the original fuse probably isn't made to handle the additional accessory load, and 2) the accessories aren't really protected by this fuse. <br /><br />Thanks again

 

[Dunaruna]

Re: Losing Sleep -- Calling in the Big Guns

On some boats (and cars) the type of starter, length of wiring loom, position of battery and other load factors cause a voltage drop at the solenoid. A starter solenoid relay allows full battery voltage to kick the solenoid into life. If yours is cranking o/k - don't worry, you don't need one.<br /><br />The one and only fuse is protecting everything but your right, if you are going to add accessories you will need to fuse each and every one individually. One of the best ways is to run a new wire from the battery to a fuse box and then jump your accessories off the fuse box, a fuse box with illuminated switches is very common. The new wire should have a curcuit breaker near the battery. The aim of the game is to protect against a short and minimise the load on switches and wiring. <br /><br />Often with older boats every owner has had a play with adding stuff and under the dash starts to look like a 'birds nest of wiring'. You might consider starting afresh and updating to a new loom and incorporate your new accessories at the same time - just a thought.<br /><br />BTW, the only wire I have on my ignition switch accessory terminal is the CD player.<br /><br />Aldo

 

[spacemanpete]

Re: Losing Sleep -- Calling in the Big Guns

I re did the wiring to the gauges this weekend. Everything is newly wired, crimped and shrink wrapped. I haven't hooked up the ammeter to it yet. . . next I'm going to add a separate fuse box for all the non-engine items as has been suggested.<br /><br />One last thing. As said before, the engine wiring is on the one main fuse. Should I protect each of the individual runs with their own (smaller) fuses? I could switch the old bus bar out and install a fuse box. Or is this unnecessary . . ?

 

[Dunaruna]

Re: Losing Sleep -- Calling in the Big Guns

It's an old system, rewiring with a new fusebox is a judgement call - depends on how badly the wiring looms and connectors etc. are deteriorated.<br /><br />That main fuse protects all the basic engine functions (as per the scematic), you will need to add a fuse for any extras that you may fit such as nav lights, radio etc. The easiest way to do that is through a fused switch panel. It also allows you to easily add accessories in the future.<br /><br />Aldo

 

[spacemanpete]

Re: Losing Sleep -- Calling in the Big Guns

So here are a couple pictures for the satisfaction of knowing there was progress after all this. <br /><br />I did create a separate panel for all other circuits, and ran 8 gauge, fused with a maxi-fuse right off of the battery. <br /><br />The first picture shows how the boat was when I got it. The second picture shows the new panel on the left, but of course, most of the new wiring has not been added to it. <br /><br />

<br /> <br />

<br />Thanks again for the help.

 

[Dunaruna]

Re: Losing Sleep -- Calling in the Big Guns

In reference to the first pic - every man and his dog has had a go at that at some stage, green wires everywhere! They have jumped all the accesories of the ignition hot (big bunch of wires all together on the far right), I bet they would have replaced the ignition fuse with a monster - best to check.<br /><br />Looks like you're on the right track, nice and neat.<br /><br />Another simple thing to do is draw your own scematic when you are finished and note down the wire colors(including the new additions). It'll help if you need to repairs in the future.<br /><br />Aldo

 

[spacemanpete]

Re: Losing Sleep -- Calling in the Big Guns

Actually what they did with the ignition fuse was jump some wire across it -- no good! <br /><br />I've got the scematic done . . . very helpful to keep things straight instead of trying to picture it all in my head. Peter