Friday, 29 January 2016

Alternator update

Many thanks to all who have commented with suggestions and sympathy (that's how I'm reading yours, Jim!). Dave Ward has gone out of his way to help - thanks Dave.

I have spoken to Ed Shiers of Four Counties Marine Services who would come and fit a new alternator for £360. Dave Ward has found a potential replacement for £182.40. I have contacted West Lancs Auto Electrics who have quoted £145 including delivery, but when I mentioned the external black box thingy they were surprised, saying that the Sterling ABC should look after the regulation. I don't know why an external regulator has been added, as I understood alternators to have internal regulators, as a rule.

So ... £360 for someone who (presumably) knows what he is doing to come and sort things out ...

Or £182 for a Prestolite equivalent alternator which I could pick up from home ...

Or £145 for a like-for-like Prestolite from West Lancs to be delivered.

I have an idea what I'm going to do, but I'll let you all have your say if you like (and I think I know what you're going to say!)

Here are some more photos, starting with the space where the alternator goes.

This bolt goes through the mounting holes, securing it to the black cylindrical protrusion from the engine foot.

Here is the alternator with its external black box.

This is the label ...

... on the black box ...

... and this is the other side of the black box. The wires disappear into a slightly squishy rubbery compound.

I will let you know what happens next!

6 comments:

John Lomax said...

Hi West Lancs Autos really know their stuff, i can't speak too highly of them. they completely rebuilt my expensive (£1300) bosch marine alternator at a fraction of the replacement cost. I had an alpha pro external controller ie regulator rather than the sterling and could have opted for a like for like rebuild but in the interests of simplicity and any subsequent guarantee issues i opted for rebuilding it with an internal regulator and self exciting (also means a simple 2 wire connection). Similar possibilities should apply to your Prestolite (giving the option of not using the Sterling) and don't affect the price greatly. If you wish to discuss the pros and cons
of each option please call me 07787427094.

Dave Ward said...

I put "IH811" into Google and it turns out to be a common Chinese manufactured regulator intended for Hitachi alternators! A UK supplier is selling them for about £13 - you can probably get them for less on eBay. I'll bet the internal one packed up, and this was a cheaper method of getting the alternator going again... It appears to be fixed at 14.3volts. Many modern alternators have the regulator combined with the brush pack (for convenience, or to force you to buy bits you don't need?), so it would be interesting to dissect your old unit and see what has been done - hint, hint!

Anonymous said...

Just wanted too say whatever you decide we used Ed Shiers to recently to fix our Eberspacher, he certainly does know what he's doing and we couldn't recommend him enough. We were also telling someone recently how impressed we were with him and they said one of the very well respected marinas has been trying to get him to go and work for them for ages. We're not related or even friends but for those of us who aren't mechanicallyi minded he did an excellent job at a fair price! Paula

John Lomax said...

i understood that the sterling was connected to this alternator, this device is an external regulator designed to control the field coil voltage/current in the rotor to provide more effective battery charging profile than an automotive regulator. When the sterling is fitted the standard regulator is kept so that if the sterling fails the alternator reverts to standard and still charges. Irrespective of whether the chinese regulator was fitted to replace the original regulator in the prestolite or because the sterling had failed your earlier post said you were measuring 13-14.4 v at the domestic battery with the engine running and back to around 12.7v shortly after switch off these voltages are consistent with a functional regulator. If you had a low voltage/no voltage regulator failure you would not see the measured running voltage. If you had an overvoltage regulator failure only and the stator windings and diode pack were ok then you would see voltages typically over 15v at the battery and overcharging. You also said that the alternator got hot quickly and there was a smell of overheating. Given no sign of batteries having taken on charge this suggests insulation breakdown in either the rotor or stator windings (or both) and maybe also failure pf the rectifier pack. If you don't want to take the plunge for a replacement alternator you could dismantle it and look for evidence of overheating, it is fairly obvious how it is broken down, the only tricky bit is retracting the brushes on reassembly but a couple of bent paper clips does the job. If you are really lucky you might get away with a new rectifier pack, but unless you can test the windings you wouldn't know until you put it all back together and run it and even then there is no predicting how long it will last if you have had partial breakdown of the insulation.

Dave Ward said...

"I understood that the sterling was connected to this alternator, this device is an external regulator designed to control the field coil voltage/current in the rotor to provide more effective battery charging profile than an automotive regulator"

Sorry John, Sterling do indeed market external regulators, but the AB12210 fitted to Halfie's boat is NOT such a device, and has no connections to the alternator apart from the main output. The small "potted" device in these pictures is a separate matter entirely, and the reasons for it are still unclear. I downloaded the Sterling manual and it's specifically intended for people who don't want to modify their alternators. It is actually a diode splitter with some form of voltage booster wired across the domestic output. It is intended to provide the same multi-stage charge control as a mains battery charger, or modified alternator, but from a fixed voltage input.

Halfie said...

Again, many thanks to all who have commented.

John, thanks for your recommendation of West Lancs Autos. I had a longish conversation with them but couldn't convince the man I was talking to that the Sterling had no connection with the alternator other than the main output from it. As Dave has said, this is indeed the case.

Paula, after last night's fitting of the new alternator and it seeming to have made no difference I was thinking I should have got Ed to do it. I'm sure he would have had a proper DC clamp ammeter to give instant measurements of charging currents etc. He might have been able to identify the various dangling and disconnected wires in the engine 'ole too.

I'll do a new post and reveal the latest developments.