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Post by lollygagger on Nov 27, 2017 9:35:10 GMT
I'm selling no.1 boat.
It needs a fair few revs to get the charge light to go out. I don't like to do this to a cold engine so I warm it up first, but it won't look good to a prospective purchaser and the boat shakes a bit! It needs more revs than I would ever use under way, it's an old Perkins 3 cylinder with a big prop.
Q. How to make it go out at lower revs? A bigger bulb (more watts). I'll check what's fitted when it stops raining.
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Post by lollygagger on Nov 27, 2017 9:55:10 GMT
It's a 2w bulb at the mo. Looks rather old fashioned, no doubt a pita to source a replacement.  |
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Post by lollygagger on Nov 27, 2017 10:49:36 GMT
I've done some homework and the bulb is Lucas L281. There are no other wattages available in this size and fitting so that plan is scuppered but I could add another bulb in series to make 4w?
Or am I barking up the wrong tree anyway?
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Post by markhez on Nov 27, 2017 11:13:23 GMT
Parallel not series, but it probably won't do anything. is there no scope to fit a larger engine pulley or smaller alternator pulley?
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Post by lollygagger on Nov 27, 2017 12:02:03 GMT
Parallel not series, but it probably won't do anything. is there no scope to fit a larger engine pulley or smaller alternator pulley? From memory I haven't had to give it as many beans in the past. The engine always starts on the button so the battery has had an easy life plus gets charged on a land line. Maybe alt brushes? I'll have to investigate more, I was working front to back through the boat and didn't get to the engine before circumstances changed and I needed a bigger boat. Not sure if there's an ammeter built in even! |
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Post by Graham on Nov 27, 2017 12:26:00 GMT
I assume it it used to go out when it should or has it always been like this?
Basic checks I would do
Check the alternator belt is correctly adjusted - general rule on most boats less than 10mm movement on the longest side when pushed firmly.
Check all the cable connections to the alternator and the panel. Take them off, clean and put back on at a minimum.
Check the battery voltage is the battery down
Check connections on the battery particularly the smaller wires if any.
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Post by Telemachus on Nov 27, 2017 13:32:05 GMT
I'm selling no.1 boat. It needs a fair few revs to get the charge light to go out. I don't like to do this to a cold engine so I warm it up first, but it won't look good to a prospective purchaser and the boat shakes a bit! It needs more revs than I would ever use under way, it's an old Perkins 3 cylinder with a big prop. Q. How to make it go out at lower revs? A bigger bulb (more watts). I'll check what's fitted when it stops raining. Once the light goes out, does it stay out at idle? If so you should be able to improve things by sending more current through the lamp circuit. If it comes back on as soon the revs drop, the issue is a more fundamental one - pulley ratios, faulty alternator, loose belt etc. But presuming the former, you can try a higher wattage bulb. Some people put a wirewound resistor in parallel with the bulb circuit as an alternative to a higher wattage bulb. Maybe 47 ohm 5 watt ceramic resistor. It will get very hot with the ignition on and the engine not running so bear that in mind when locating it. I the boat has had a split charge relay added, this can sap current that would otherwise go to kick start the alternator and the standard solution to that is the higher wattage bulb or resistor in parallel. This of course presumes its a standard alternator excited via the warning light. It probably is, but not all are. |
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Post by JohnV on Nov 27, 2017 18:37:17 GMT
One of the important questions already asked is "did it always behave like that" If this is a new thing and nothing has been altered then it suggests the regulator may be the cause
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Post by Deleted on Nov 27, 2017 18:42:34 GMT
A little idea of mine is for a few of the mechanically & electrically knowledgeable members of TB to get a van and to go round the country sorting out boaters' problems. Instead of 'The A-Team' they'd be known as 'The T-Team'. As a small business. It could be a fun thing to try for a year. Nothing as official as RCR, just by word-of-mouth.  T for Twat ? |
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Post by Deleted on Nov 27, 2017 18:45:57 GMT
I don't really "go there" on alternators but was once told that if the wire to the IND connection is too small it can cause problems with alternator excitation at low speeds. I might have misunderstood what the bloke was explaining to me (I had a Russell Newbery engine which needed to be revved up a bit to get the indicator lamp to go out.
Another thing was bulb wattage.
I don't really know. I just put a push button switch in so I could manually excite it.
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Post by lollygagger on Nov 27, 2017 19:56:23 GMT
I don't think it's always been so bad. What with one thing and another it didn't get started for a year so it's hard to remember but if it were a problem before I feel sure I would.
The charge light stays off once off.
The belt isn't slipping.
It's been dread weather here today and I didn't get another go at it.
My money is on a poor connection, I'll report back when I've had a good prod.
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Post by Deleted on Nov 28, 2017 4:58:26 GMT
I don't think it's always been so bad. What with one thing and another it didn't get started for a year so it's hard to remember but if it were a problem before I feel sure I would. The charge light stays off once off. The belt isn't slipping. It's been dread weather here today and I didn't get another go at it. My money is on a poor connection, I'll report back when I've had a good prod. How many hours has that alternator done? You mentioned the possibility of worn brushes earlier. It could be that. If they were badly worn you'd probably find it will struggle with large loads (check ammeter) and you may see the bulb flickering faintly at low revs. |
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Post by tonyb on Nov 28, 2017 7:42:46 GMT
I don't really "go there" on alternators but was once told that if the wire to the IND connection is too small it can cause problems with alternator excitation at low speeds. I might have misunderstood what the bloke was explaining to me (I had a Russell Newbery engine which needed to be revved up a bit to get the indicator lamp to go out. Another thing was bulb wattage. I don't really know. I just put a push button switch in so I could manually excite it. In theory that is correct, especially if the bulb is at the front of the boat and the alternator at the back but on a typical narrowboat very unlikely. The current carried in the warning lamp cable is so small the voltdrop caused by easily available cable will also be very small so bets ignored as a potential source of the problem in this case. Apart from that nothing to add, all has been said except to warn that some warning lamps that have a lens/body that looks like the OP's use a grain of wheat (dolls house) bulb and along with LED warning lamps are unsuitable for al;ternator warning lamps because they do not pass enough current. |
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Post by lollygagger on Nov 28, 2017 9:01:20 GMT
I don't think it's always been so bad. What with one thing and another it didn't get started for a year so it's hard to remember but if it were a problem before I feel sure I would. The charge light stays off once off. The belt isn't slipping. It's been dread weather here today and I didn't get another go at it. My money is on a poor connection, I'll report back when I've had a good prod. How many hours has that alternator done? You mentioned the possibility of worn brushes earlier. It could be that. If they were badly worn you'd probably find it will struggle with large loads (check ammeter) and you may see the bulb flickering faintly at low revs. "If" it is the original engine alternator it was second hand 30 years ago... The boat is as good as sold but I'd still like to sort out this problem before I hand it over. |
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Post by Deleted on Nov 28, 2017 9:06:06 GMT
Get a new generic alternator and try it? If it doesn't work either then put old one back and find what the problem was then just keep the alt as a spare.
I had a similar problem on a 20 year old alternator which was just very dirtyand nackered I just replaced it and all working now. Didn't really seem worthwhile refurbishing it as a new one isn't expensive anyway, unless its a special alternator. Mine was an a127 type.
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