JohnC Posted November 29, 2005 Report Share Posted November 29, 2005 Can anyone tell me what spec alternator the 6 uses? My alternator has just given up the ghost, and as far as I can tell it has no legible identification markings. It does have a Lucas sticker, but only the word Lucas is faintly visible; the rest of the label is white (I know it used to have numbers on it, but I don't know what they were...). I'm pretty sure the alternator was a recon unit, and a straight swap for the one it replaced. This time I'd prefer to fit one with a higher output as I have a Bosch pump and electric fan. I don't want to modify any fittings, and I'd prefer to use the existing connector block, but the latter isn't critical. So, any advice? What is the original spec (and part number)? What would be a good uprated alternative? Thanks in advance, John Quote Link to post Share on other sites
Peter Douglas Winn Posted November 29, 2005 Report Share Posted November 29, 2005 If I am correct the following is what you want. Lucas 15ACR Alternator was supplied up to CP52785. This has an internal regulator and 28 amps. Lucas 16ACR Alternator was supplied from CP52785. Which I believe has 34 Amp output. The alternatives are Lucas 17ACR 36 Amps or Lucas 18ACR 45 Amps. Just watch the wiring and make sure you get it connected correctly. Quote Link to post Share on other sites
BryanD Posted November 29, 2005 Report Share Posted November 29, 2005 Just a thought ... Will the standard ammeter be Ok if you upgrade the Alternator to 45 Amps? I suspect the standard one is a 30A type. Quote Link to post Share on other sites
jean Posted November 29, 2005 Report Share Posted November 29, 2005 John, I had the alternator on my 6 replaced by a 34A Lucas LRA100 , now it's on my TR3. Depending on your actual alternator this one only has 2 wires a+ and IND as it's fitted with an internal bridge. For the rest it looks exactly as the original. According to the box it's used on many english cars lik Land Rover and Ford. To compensate the extra load on the A-meter you can put an xtra wire direct to the battery, it has twin + outlet connectors, this is what I did on my TR3. Jean Quote Link to post Share on other sites
vanflyer Posted November 29, 2005 Report Share Posted November 29, 2005 The standard ammeter is rated for 30A, so a higher output altenator will cause problems. Lucas did a 60A ammeter if you can find one. the alternative is to get a voltmeter, which is wired across the battery as opposed to inline. An alternayive altenator is available, it was installed in the 1979 Ford Fiesta, there was also a GM part that will fit, I can't remember the model though. Quote Link to post Share on other sites
paul gardner Posted November 29, 2005 Report Share Posted November 29, 2005 I am not convinced that the standard TR6 ammeter is rated at 30 amps because the Lucas 16 ACR, rated at 34 amps, was a standard fit from CP52785 onwards without any corresponding change in ammeter rating. Furthermore, both Moss and Rimmers offer the 18 ACR, rated at 45 amps, as an alternative without warnings about ammeter modifications/replacements. Also, in their additional notes about plug wiring changes needed when changing from a 15 AC to a 15ACR alternator, Moss note that no further changes are needed to accommodate alternator upgrades beyond 15/16ACR types. yours, Paul Quote Link to post Share on other sites
jean Posted November 29, 2005 Report Share Posted November 29, 2005 As far as I know the original alternator on my 1970 TR6 was 28A. There is no problem to upgrade it to 40, and I see no reason to remove the A-meter for safety if you leave the wires behind the dash. As I mentioned before, to be on the safe side add an xtra wire. I have now a 60A alt. with the standard wiring, I just have to watch that the battery is staying full loaded. This way there is little risk to toast the wires. It is anyhow not advised to re-load a flat battery via the alternator, always use an external charger. At start up the A-meter on my 6 is showing full charge, but the needle is centred in a few seconds. Jean Quote Link to post Share on other sites
Victor1155 Posted November 29, 2005 Report Share Posted November 29, 2005 Hi John Having just had a similar experience with the alternator on my 6 I went down the route of fitting a higher output version, the one I fitted was destined for a 1988 Rover 416 and is rated at approx 55 amps. When fitted the ammeter needle on the standard ammeter disappeared out of sight beyond the positive zone. To rectify this I fitted a Lucas 60-0-60 ammeter and all is well the ammeter shows a healthy charge when driving at all times. So I second what vanflyer says fit a 60-0-60 ammeter and avoid damaging the original +/- one that is fitted as standard. Steven H :blues: Quote Link to post Share on other sites
jonlar Posted November 29, 2005 Report Share Posted November 29, 2005 Hi John, whilst you're replacing it, go for the higher output 18ACR (718742 or 218742 - Lucas No. 23739A) or LRA100/102 type, but as Steven says above, also uprate Ammeter for a 50 or 60A one, or safer again change to Voltmeter, so you haven't got full battery current running in behind the dash and through the bulkhead. If you retain ammeter, make sure grommets are in good nick! If you need any more part nos. I'll check in JL(HRH PoD!)'s bible for you. Quote Link to post Share on other sites
jemgee Posted November 29, 2005 Report Share Posted November 29, 2005 I use an uprated Lucas LRA 460 from a local auto electrical shop. Only down side is the diameter is bigger and now have to use the uj plug spanner on no 1 cylinder rather than a straight tubular box spanner - but then you have to use a uj plug spanner on 4 or 5 cylinders which are fouled by the distributor. As Jean says on start up it goes to max but then centres after a few seconds. I like it because at tick over the output is sufficient to stop a constant discharge which always worried me when sitting in summer traffic with the Kenlowe pulling juice out of the battery. I felt this was sooner or later going to result in a battery failure in the middle of a long traffic jam. Quote Link to post Share on other sites
jonlar Posted November 30, 2005 Report Share Posted November 30, 2005 you have to use a uj plug spanner on 4 or 5 cylinders which are fouled by the distributor If you take the dizzy cap and rotor arm off, you don't need to use UJ - safer for the leads and cap - just make sure leads are labelled. Quote Link to post Share on other sites
jemgee Posted November 30, 2005 Report Share Posted November 30, 2005 Should have thought of that!! Strange thing was when I took the car to the international in 2003 and had a mobile tune up the technician started off by turning the whole distributor about 90 degrees (if I remember correctly) but only found minor adjustments to tuning was needed. Up to that point I had had no problems with the old box spanner, but next time I came to check the plugs I had to go and buy a modern uj spanner I think it is the spring clamp onto the cap which gets in the way now Quote Link to post Share on other sites
JohnC Posted December 2, 2005 Author Report Share Posted December 2, 2005 Thanks for all the info - I'll see where I can get one of these 18ACR beasties. Jonlar - Thanks for the offer; I'll let you know if I get stuck. I've wondered before about the advisability of loadsa current flowing behind the dash; I would like to change to a voltmeter if that will eliminate some of the risk. I guess I now need to work out how... On the other hand, Jean's idea sounds nice & simple - does it mean that the ammeter is showing half the actual charge/discharge? Cheers, John Quote Link to post Share on other sites
Andy Moltu Posted December 2, 2005 Report Share Posted December 2, 2005 If you take the dizzy cap and rotor arm off, you don't need to use UJ - safer for the leads and cap - just make sure leads are labelled. I guess you'd generally have to take the plug lead off to put the plug spanner on anyway :: Quote Link to post Share on other sites
jonlar Posted December 2, 2005 Report Share Posted December 2, 2005 If you take the dizzy cap and rotor arm off, you don't need to use UJ - safer for the leads and cap - just make sure leads are labelled. I guess you'd generally have to take the plug lead off to put the plug spanner on anyway :: I meant where the leads push into dizzy cap! Quote Link to post Share on other sites
Guest ron Posted December 2, 2005 Report Share Posted December 2, 2005 Don't take this as gospel but several years ago I was told by the guy in my local auto shop that the 16, 17 and 18 Lucas alternators were interchangeable, even if the mounting was the wrong hand it was only a matter of removing the through bolts and turning it. By the way I can remove plugs 4 and 5 with a standard socket and extension without removing the distributor cap----------but I do remove the leads from the plugs Ron Quote Link to post Share on other sites
Victor1155 Posted December 2, 2005 Report Share Posted December 2, 2005 Ron's correct, all of the Lucas16, 17 & 18 ACR alternators can be 'spun' to give the correct 'hand' for mounting to the engine. However if it is an old unit that you intend to use be advised that the stator windings can often stick fast to either end brackets giving the impression that it will not turn. This can be resolved with a sharp tap with a soft faced mallet to free the sticking parts. Once free simply turn the front bracket to the required position and you have the alternator that you need. Steven H :blues: Quote Link to post Share on other sites
jean Posted December 2, 2005 Report Share Posted December 2, 2005 John, the A-meter is nothing more than a big wire fitted in a loop inside the housing. The needle connected to an iron is measuring the magnetic field created by the current as well as the direction of the current flow. If the additional wire is of the same resistance as the A-meter wire, the indication will be split by 2, this means the indication on the meter will be in accordance with the resistance of the separate wires. That's how I understood the story. Anyhow I did not care about any amount, I was just interested in charge or discharge, and that's what the meter indicates. Jean Quote Link to post Share on other sites
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