Alternator Wiring

[Nobag]

Hello All

 

We recently bought an old Harborough Marine and have used the boat just twice, this weekend when we went to the boat, the batterys were flat and i used a powerpack to jump start the engine, with the engine running i put a multimeter across the battery terminals and the reading was 11.6. i checked the wire connections on the alternator and they were secure.

 

After looking at posts on here, some have said that the alternator gets activated by the power from the ignition light. on this boat the ignition light is not wired at all. is it possible for the alternator to work as it is wired at present, both wires are coloured red and one is connected to the large spade connector while the other wire is on the smaller spade connector next to it. the engine is a 2 cylinder lister.

 

I am sorry if this has been brought up before, but i could not find any info.

 

Cheers

 

[alan_fincher]

If the smaller connection is not connected via a warning light, what is it connected to, please ?

 

That's rather relevant!

 

Alan

[Nobag]

If the smaller connection is not connected via a warning light, what is it connected to, please ?

 

That's rather relevant!

 

Alan

I am sorry, i did not have chance to trace where the wires connected to properly, the one with the smaller spade appeared to run back towards the batterys, the wire with the larger spade connection joined the wiring loom back into the boat, where i thought it may have gone to the volt meter.

 

I think i will need to have it rewired, on the instrument panel there are gauges for water temp, oil pressure and other things that the lister does not have.

 

Cheers

[alan_fincher]

I think you will need to be able to say what is connected where before anyone can advise you too well.

 

The norm is that it is excited via the warning light, in my limited experience.

[Sir Nibble]

That is an A133 alternator. As others have said, the small connector SHOULD connect to a warning light, the alternator will not cut in without it. Sometimes people try shortcuts to connect this to the starter or ignition etc, it doesn't work and damages the unit.

[Nobag]

That is an A133 alternator. As others have said, the small connector SHOULD connect to a warning light, the alternator will not cut in without it. Sometimes people try shortcuts to connect this to the starter or ignition etc, it doesn't work and damages the unit.

 

Thanks

 

I think i will buy a new alternator off E-Bay, if i run a wire from a live on the ignition switch to the ignition lamp and then on to small connection on the alternator. then another wire from the large connection straight to the battery positive terminal work, i know i will lose the voltmeter, but it is not doing much now.

 

Cheers

[estwdjhn]

That is the simplest option.

 

I assume that you have common cabin/engine batteries, otherwise you may need somthing to control the charging relay that seperates the cabin and engine batteries.

[Tony Brooks]

Thanks

 

I think i will buy a new alternator off E-Bay, if i run a wire from a live on the ignition switch to the ignition lamp and then on to small connection on the alternator. then another wire from the large connection straight to the battery positive terminal work, i know i will lose the voltmeter, but it is not doing much now.

 

Cheers

 

 

If it is a Voltmeter, and looking at the cable size I suspect it may be an ammeter, simply connect the "disconnected" cable side to any suitable 12v positive that is close by. It may not give you battery voltage bit it will be very close when there is little other electrical load.

 

If the meter is what I suspect it is then it is probably not much more than an indication/toy anyway.

[Nobag]

If it is a Voltmeter, and looking at the cable size I suspect it may be an ammeter, simply connect the "disconnected" cable side to any suitable 12v positive that is close by. It may not give you battery voltage bit it will be very close when there is little other electrical load.

 

If the meter is what I suspect it is then it is probably not much more than an indication/toy anyway.

Thanks

But i think i will try and keep it simple with just the wires to the battery and warning light, when i looked into the case that house's the gauges and switches,

it was like a birds nest with wires everywhere. i have been looking at your web site, so hope to gain lots of info from there.

 

Cheers