Jeff Cotter Posted November 8 Report Share Posted November 8 Hi All, I need some advice on "The dark side", (Electrics) :-). I am chasing a fault around my electrics, (TR4A IRS 67). I cant get a charge reading. And the ammeter does not show a positive charge. The following hopefully helps... Action taken... Changed Dynamo. Ammeter shows negative when engine stopped and lights put on. changed lead from dynamo to control box. run test from dynamo 4v at 1500 rpm gen light on dash goes out when engine running mustimeter across battery shows no charge, just 12v with engine stopped or running. I have started and run the car on numerous occasions so I suspect the battery is charging somehow Many thanks I really appreciate the forum and all the help the community provides.... Jeff C. Quote Link to post Share on other sites
RobH Posted November 8 Report Share Posted November 8 It sounds as though the dynamo may not be generating enough output to close the cut-out contact in the regulator box. The ignition light is connected between the dynamo output and the battery so when the dynamo output is low, there is a big difference and the lamp is bright. As the output increases the voltage across the lamp drops until it goes very dim. When the dynamo output is high enough the cut-out contact closes to connect the dynamo to the battery and the bulb is shorted out. However, if the output never gets high enough, or if there is a fault/bad adjustment in the regulator, the cut-out will not close. The ignition lamp may not go out entirely but glow very dimly. With the engine running at about 2500rpm, what voltage can you measure at the D terminal on the regulator? Since you have already changed the dynamo, it may be that the regulator is faulty or the connection to the dynamo field is poor (brown/green wire from the F terminal). Also check that the earth connection on terminal E is good. Quote Link to post Share on other sites
Jeff Cotter Posted November 8 Author Report Share Posted November 8 Thanks Rob, i'll follow your guidance, many thanks... Quote Link to post Share on other sites
harlequin Posted November 8 Report Share Posted November 8 (edited) Hi Jeff I have just been down this road with my TR3A, I found a testing routine on the Internet ( file attached) which was very helpful. My problem turned out to be the regulator, I bought a new one which proved to be faulty. When I returned it the vendor said he has a lot of problems with them and that there is only one manufacturer that supplies all the vendors. To make things reliable I bought a solid state gizmo that fits inside the original box and so far so good, the gizmo came from these people http://www.dynamoregulator.com/ George lucas.pdf Edited November 8 by harlequin Quote Link to post Share on other sites
Jeff Cotter Posted November 8 Author Report Share Posted November 8 Hi thanks George, just taking a look at the solid state, ultimately Solid/s, on a tour is piece of mind..... cheers jeff Quote Link to post Share on other sites
trchris Posted November 8 Report Share Posted November 8 Hi Jeff Did you flash the new dynamo? No l don’t mean like that lol, earth the dynamo body the run a wire from positive side of battery and touch the F terminal a couple of times (other way for positive earth) as Rob says check the voltage at the dynamo and at the regulator terminals sometimes you will have to adjust the points inside Chris Quote Link to post Share on other sites
Jeff Cotter Posted November 8 Author Report Share Posted November 8 6 minutes ago, trchris said: Hi Jeff Did you flash the new dynamo? No l don’t mean like that lol, earth the dynamo body the run a wire from positive side of battery and touch the F terminal a couple of times (other way for positive earth) as Rob says check the voltage at the dynamo and at the regulator terminals sometimes you will have to adjust the points inside Chris Hi Chris yeh did that on the old and new Dy'mo, the old one tested fine but for£60 i put a new one on. I also ran the test George refers to as i also have the very useful doc attached above. I will keep searching for the problem.... cheers. Quote Link to post Share on other sites
Ransomes256 Posted November 8 Report Share Posted November 8 I had similar problems and finally also went the full electronic regulator route but from this company info@dynamoregulatorconversions.com Wish I had done it years ago. Stayed positive earth. Take care to read different company statements on what the regulator conversion includes as some only cover the voltage output not controlling the charge rate. Neil Quote Link to post Share on other sites
RobH Posted November 8 Report Share Posted November 8 It may prove useful to clean the contacts of the cut-out and the field regulator but do it gently so nothing gets bent and use very fine glass-paper, or a diamond spatula. Do not attempt any adjustment of the regulator settings unless you really know what you are doing and have the appropriate test kit as specified. They used to say that people who fiddled with the regulator kept Lucas in business. The new regulators available are of far-east manufacture and some are of dubious quality - particularly the metal used for the contacts. The original Lucas ones were expensive for a reason. If you decide to go for one of the DVR3 electronic modules, make sure you get one with the correct current rating to match the dynamo (22 Amps) as they come in a variety of settings: http://dynamoregulator.com/products.html Quote Link to post Share on other sites
harlequin Posted November 8 Report Share Posted November 8 1 hour ago, Jeff Cotter said: , ultimately Solid/s, on a tour is piece of mind..... cheers jeff That was my thought as well, the last thing you need on a dark night in rural France is the dodgy regulator playing up! I looked at dynamoregulatorconversions but at £200 I went for the thing I got for £85 and a bit of DIY George Quote Link to post Share on other sites
Z320 Posted November 8 Report Share Posted November 8 8 hours ago, RobH said: It sounds as though the dynamo may not be generating enough output to close the cut-out contact in the regulator box. The ignition light is connected between the dynamo output and the battery so when the dynamo output is low, there is a big difference and the lamp is bright. As the output increases the voltage across the lamp drops until it goes very dim. When the dynamo output is high enough the cut-out contact closes to connect the dynamo to the battery and the bulb is shorted out. However, if the output never gets high enough, or if there is a fault/bad adjustment in the regulator, the cut-out will not close. The ignition lamp may not go out entirely but glow very dimly. With the engine running at about 2500rpm, what voltage can you measure at the D terminal on the regulator? Since you have already changed the dynamo, it may be that the regulator is faulty or the connection to the dynamo field is poor (brown/green wire from the F terminal). Also check that the earth connection on terminal E is good. Good explanation from Rob! I recommend to start the engine, run it on idle and put the cover of the regulator off. Rev the engine gently up and observe what the cut-out does. Does it close the generator ampmeter must show a charge, if not the contacts could be dusty, like Rob explains next. Original the contacts of the cut-out are made from silver for low resistance, the ones on the regular are made from wolfram for more durability. Don‘t kill them by cleaning (do what Rob recommends) Ciao, Marco Quote Link to post Share on other sites
Z320 Posted November 8 Report Share Posted November 8 Btw I still use the RB-106, it works without problems. And got an old original with the correct Lucas / TR44 number needles as a spare. Quote Link to post Share on other sites
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