Battery doesn't seem to be charging

[Tony Brooks]

7 minutes ago, hackenbush said:

Yes, when I connected the wires there was a leap on the voltometer

OK then the alternator is probably OK but there is a short on the warning lamp to alternator wire, the warning lamp that goes on is NOT the charge warning lamp, or something incorrectly wired, probably under the instrument panel. Could be a blown warning lamp bulb if you have another warning  light that does not work.

If you disconnect both ends of the thin red warning lamp cable and run another one I expect it will all work again BUT if there is a short it might be chaffing its way into a wire that can set fire to the wiring harness so it is best to find the short of you can rather than just run another cable.

 

3 minutes ago, hackenbush said:

Engine idling, warning light disconnected, reading on voltometer:

 

That's good, the batteries are still fairly well charged.

Edited March 22, 2017 by Tony Brooks

[hackenbush]

The oddity is when the engine isn't running the reading is 12.08

Edited March 22, 2017 by hackenbush

[hackenbush]

Ignition setup. Very basic!

cant work out what the errant wire with what looks like an ancient fuse sticking out is doing? It was tucked at the back I've pulled it out so it can be seen

 

[nicknorman]

So when you touched the alternator terminals together and got the alternator to start charging, what did the warning light do? Was it still illuminated or did it go out? If the latter, perhaps it is a different warning light for low oil pressure etc. If the light remained on there is definitely a short circuit to -ve somewhere.

[Tony Brooks]

Just now, hackenbush said:

The oddity is when the engine isn't running the teasing is 12.08

I assume that you mean the testing is 12.08 volts.

OK, so the battery is flatter than the 14.08 suggests. With the alternator running at maximum output (very flat battery) the charging voltage could be as low as 13.4 volts but as yours is above 14 volts it suggest the charging current is low and hence my fairly well charged comment. Its no big deal because we seem to be on the track of the fault.

[nicknorman]

3 minutes ago, hackenbush said:

The oddity is when the engine isn't running the teasing is 12.08

Not that odd, the voltage will drop back fairly quickly to the original voltage if the engine was only run briefly. Did you have the meter probes actually on the battery terminals, or somewhere else?

Anyway, at least you have a means to get the alternator charging. It should continue to charge until you stop the engine again, so you have a way to charge your batteries.

[Tony Brooks]

2 minutes ago, nicknorman said:

So when you touched the alternator terminals together and got the alternator to start charging, what did the warning light do? Was it still illuminated or did it go out? If the latter, perhaps it is a different warning light for low oil pressure etc. If the light remained on there is definitely a short circuit to -ve somewhere.

Nick - I told him to leave the terminal off so the lamp would never have been on. I told him this because if there is a short he would stand a good chance of blowing the field diodes as a high current went through them to the short.

[nicknorman]

4 minutes ago, Tony Brooks said:

Nick - I told him to leave the terminal off so the lamp would never have been on. I told him this because if there is a short he would stand a good chance of blowing the field diodes as a high current went through them to the short.

Yes but I mean with the wire still disconnected and with the alternator running and charging, did the bulb stay on or go out. Just a way to double check that we are talking about the correct light. You say "the lamp would never have been on" but wasn't the lamp on with or without it being connected to the alternator? Or am I confused?

[Tony Brooks]

5 minutes ago, hackenbush said:

Ignition setup. Very basic!

cant work out what the errant wire with what looks like an ancient fuse sticking out is doing? It was tucked at the back I've pulled it out so it can be seen

 

You seem to have  two wires on one side of the warning lamp. The side that shoudl run to the alternator. The extra wide seem to have  silver cylindrical thing on it but what is after the silver thing is not clear. If that extra wire is touching metal then it would explain your symptoms.

Without more info and based only on what I can see I would say that if there are two wires on the warning lamp then the one with the silver thing needs removing BUT the silver thing might be a resistor that should be connected across the warning lamp to aid energisation. however it does not look like any resistor I have seen. it looks more like a radio suppressor. At the least make sure the free end of that wire and the body of the silver thing are not touching any metal.

[nicknorman]

 

[Tony Brooks]

1 minute ago, nicknorman said:

Yes but I mean with the wire still disconnected and with the alternator running and charging, did the bulb stay on or go out. Just a way to double check that we are talking about the correct light. You say "the lamp would never have been on" but wasn't the lamp on with or without it being connected to the alternator? Or am I confused?

I think that we have established that the bulb stayed ON when the D+ cable was disconnected from the alternator so that indicates a possibility of a short. I have pointed out that the lamp in question may not be a charge warning lamp but I doubt Mr H would know what it is - hence my request for photos. From the photo it looks as if it may well be a charge warning lamp but who knows at this stage.

[bizzard]

5 minutes ago, Tony Brooks said:

I think that we have established that the bulb stayed ON when the D+ cable was disconnected from the alternator so that indicates a possibility of a short. I have pointed out that the lamp in question may not be a charge warning lamp but I doubt Mr H would know what it is - hence my request for photos. From the photo it looks as if it may well be a charge warning lamp but who knows at this stage.

Looks like there might be a third wire connected to that warning lamp, or is it just a shaft of light reflection. Poor photo.

[hackenbush]

Due to my setup it's impossible to check the light at the same time as connecting the cables on the alternator.

however, the warning light has always remained lit for a while at the start. My understanding was that it did this up to the point the starter battery was recharged then it switched off.

since my last post I looked along the wire and found a section which had 2 wires crimped together and it looked like it was loose. I squeezed the wires together, connected the warning light wire back to the nut and started the engine and had a look at the voltometer (which is connected firmly to battery points) and whereas before the reading remained static with engine running it has now gone up to 12.63.

any ideas what all this means?

[Tony Brooks]

1 minute ago, bizzard said:

Looks like there might be a third wire connected to that warning lamp, or is it just a shaft of light reflection. Poor photo.

I think so, the one from the switch, the one that we hope runs to the alternator plus the one with the silver thing on it. It also looks as if there is some interesting red insulating tape work at the lamp end of two cables.

[hackenbush]

7 minutes ago, bizzard said:

Looks like there might be a third wire connected to that warning lamp, or is it just a shaft of light reflection. Poor photo.

Yes poor photo sorry, but best I can do.

there is one wire going from warning light to ignition and two other wires one going from ignition to engine and the other going to alternator switch.

there is an errant wire with the odd fuse-like thing which comes out of the wire connecting warning light to  alternator

Edited March 22, 2017 by hackenbush

[bizzard]

2 minutes ago, hackenbush said:

Yes poor photo sorry, but best I can do.

there is one wire going from warning light to ignition and two other wires one going from ignition to engine and the other going to alternator switch

Alternator switch?Do you mean a split charge relay.  Or do you have a battery change over switch.

[Tony Brooks]

2 minutes ago, hackenbush said:

Due to my setup it's impossible to check the light at the same time as connecting the cables on the alternator.

however, the warning light has always remained lit for a while at the start. My understanding was that it did this up to the point the starter battery was recharged then it switched off.

since my last post I looked along the wire and found a section which had 2 wires crimped together and it looked like it was loose. I squeezed the wires together, connected the warning light wire back to the nut and started the engine and had a look at the voltometer (which is connected firmly to battery points) and whereas before the reading remained static with engine running it has now gone up to 12.63.

any ideas what all this means?

I think it means that whoever you paid to fit the alternator is an !!!!!!! unless the crimp you refer to is a butt crimp that is used to lengthen a wire. If you mean one wire in turned into two wires out then something is wrong. There should be just one wire from the warning lamp to the alternator UNLESS one of the the wires runs to a split charge relay..

1 minute ago, hackenbush said:

Yes poor photo sorry, but best I can do.

there is one wire going from warning light to ignition and two other wires one going from ignition to engine and the other going to alternator switch

This is the first time you have mentioned an "alternator switch".  In most/all installations with an ignition switch the ignition switch controls the instruments & warning lamps, energises the starter solenoid and energise the alternator. No extra switch required.

The charge warning lamp should go out immediately the alternator energises BUT it may stay on for a while unless you rev the engine.

[hackenbush]

6 minutes ago, bizzard said:

Alternator switch?Do you mean a split charge relay.  Or do you have a battery change over switch.

Split charge

[Tony Brooks]

Where is this boat? I think it needs a knowledgeable forum member to visit it to see what is what.

[Tony Brooks]

With the thin wire OFF the alternator and insulated and the ignition on try pulling both THIN wires off the split charge relay. If the bulb goes out I suspect the relay coil may have shorted out. This is a long shot. If it does go out reconnect alternator the but leave the relay disconnect (insulate the wire ends). The rev the engine and measure the voltage on both batteries. One should have a voltage that has gone up, the other should have stayed the same.

[WotEver]

23 minutes ago, Tony Brooks said:

Where is this boat? I think it needs a knowledgeable forum member to visit it to see what is what.

If it's anywhere near me I could pop over tomorrow for a quick look. 

[hackenbush]

4 minutes ago, WotEver said:

If it's anywhere near me I could pop over tomorrow for a quick look. 

I'm in Haggerston on the Regent's Canal

[WotEver]

51 minutes ago, Tony Brooks said:

I think that we have established that the bulb stayed ON when the D+ cable was disconnected from the alternator so that indicates a possibility of a short. I have pointed out that the lamp in question may not be a charge warning lamp but I doubt Mr H would know what it is...

I believe that was Nick's point. If it was oil pressure for instance then it would have gone out once the engine started. However, as the OP noted that the light stayed on and that was his first indication that anything was wrong I think we can be reasonably confident that it's the ignition light. 

Just now, hackenbush said:

I'm in Haggerston on the Regent's Canal

Ahh, about 120 miles away from me then. 

[hackenbush]

34 minutes ago, Tony Brooks said:

I think it means that whoever you paid to fit the alternator is an !!!!!!! unless the crimp you refer to is a butt crimp that is used to lengthen a wire. If you mean one wire in turned into two wires out then something is wrong. There should be just one wire from the warning lamp to the alternator UNLESS one of the the wires runs to a split charge relay..

This is the first time you have mentioned an "alternator switch".  In most/all installations with an ignition switch the ignition switch controls the instruments & warning lamps, energises the starter solenoid and energise the alternator. No extra switch required.

The charge warning lamp should go out immediately the alternator energises BUT it may stay on for a while unless you rev the engine.

I mean butt crimp. That's not to say that the whole thing doesn't have the air of bodge about it though.

one wire runs to split charge relay.

And yes, actually the light does usually go out once I give it a good rev but still, I thought the light being off or on was directly related to whether the starter battery had got enough charge before the leisure battery began charging. Could you confirm this? The reason is that after fixing the loose connection on the butt crimped wires I've been getting a different reading on the voltometer but the warning light remains on

6 minutes ago, WotEver said:

I believe that was Nick's point. If it was oil pressure for instance then it would have gone out once the engine started. However, as the OP noted that the light stayed on and that was his first indication that anything was wrong I think we can be reasonably confident that it's the ignition light. 

Ahh, about 120 miles away from me then. 

OK, not bad. What time can you pop over? I'll put the tea on

[WotEver]

The light extinguishing demonstrates that the alternator is charging.  It should always be out with the engine running fast enough to charge the batteries. 

The split charge wiring (unless faulty, which is quite possible) is (or should be) irrelevant to the issue of the alternator starting up.