Wanderer Vagabond

It is an LPW4, not an LPSW4, and the heater element is in the inlet manifold. I haven't said that I have never changed the belt, I have said that since the latest increase in slippage I haven't changed the belt; since I've had the boat (8 years) I've changed the belt more than once and the alternator at least once. It was as a result of changing the belt and tightening it back in 2016 that I wrecked the water pump bearing, which is why I have the reluctance to go down that path again. The last service I gave the boat (2 weeks ago) I looked at the pulleys and belt although I didn't take them off, and can say that the belt is in better shape than one I removed in the past, which had started to split, but still wasn't slipping to the degree that is currently occurring. It isn't a case of '...not wanting to follow advice...' it is a case of changing the pulley or glowplug relay isn't just a case of popping into the nearest Halfords, so there isn't much point in me dismantling something that, even if it is the cause of the problem, I'm not going to be able to fix where I am. The place I've got replacement alternators from is Electrostart at Daventry and I know there is a guy at Sandbach who will repair them. The main dealer for Lister parts is either Sleeman and Hawken in Teignmouth, Devon or Marine Engine Supplies at Kenilworth, I'm on the outskirts of Stoke on Trent!! If Ed can properly diagnose the problem and supply any necessary replacement parts it will be far easier than me trying to faff around on the internet sourcing them and then finding somewhere for them to be delivered to (and hoping that it is the cause of the problem). At the moment, once the start up squeal stops, everything is fine, whilst that remains the case I'll press on to see Ed, if something happens on the way (belt breaks, alternator fails,relay gives up, etc.) I'll have to deal with that when it happens.

Not sure that I'm adding any information. On the first post I said it was a Lister LPW4 and on my 4th post I said,"... I had the domestic alternator fail coming through Peterborough last year and had to run on just the engine alternator to charge both banks of batteries....." which kind of suggests that there are two alternators. I too will be interested to see if/how Ed can fix it since it has gone of for far too long.

Which doesn't really take me any further forward. I'm not sure Brian was actually saying that he didn't think it was the heater element, he seemed to be saying that it shouldn't load the domestics, which is absolutely right, they are two separate circuits. When the domestic alternator failed last year I put a 'jump' across the domestic - engine battery (and disabled the domestic alternator) so that the engine alternator would keep the domestic batteries charged until I was in a position to replace the domestic alternator, that REALLY made the drive belt squeal on start up, but once again it stopped after a few minutes. The single glow plug is in the inlet manifold, I have no idea what the relay is, or what it should be so whether it is the correct one is above my pay grade. The tachometer doesn't show low speed, it 'freezes' until the belt stops squealing and then goes online and everything is hunky dory. It shows the revs that I'm travelling at and varies according to throttle setting as I'd expect. As I say, once the belt stops squealing on start up everything is fine, no warning lights are lit, the tachometer operates perfectly and to all intents and purposes there is no problem until you turn the ignition off when the whole process starts again.

As far as I'm aware there is only the one glow plug and its in the inlet manifold. With my level of knowledge on engine electrics, if I disconnect the heater element and that stops the belt slippage, then what? I still wouldn't have much of an idea what needs replacing, control box? heater element? ignition switch? along with the expected drive belt and possibly pulley. I can wait for Ed's assessment.

I think I'll wait until Ed has a look at it, rather than poke around in an area outside of my expertise potentially creating more problems. I stick with advice I was once given which was,"Does the engine work?", "Yes", "Well don't b*gger with it then"

That is pretty much what I do, although I have no true idea what rpm the engine is running at since the tacho has frozen until the slippage stops. By ear I would guess that I'm running it at about 1000 rpm since all increasing the engine speed does is increase the slippage. None of this would explain why, once the slippage has stopped, if I turn off the ignition off and then turn it back on again without stopping the engine, the slippage starts up again. As Ed Shiers seems to suggest, it seems more likely that the problem is connected to the the engine heater elements than anything else. Hoping to get to see him sometime next week so we'll see what his view is once he's looked at the problem.