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TR2/3/3A Generator Output

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TR3MT

TR3MT

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Hello All,
_At highway speeds my amp meter reads a charge of +3 amps but when I turn the head lights on I get a steading reading of about -5 amps. Is there a way I can increase the amp output? The fan belt is tight.
Thanks for any input,
TR3MT
 
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Check the voltage at the battery with the engine running at about 2000rpm and nothing turned on. You can use the control box to adjust the voltage to be between 13.7v (if you drive the car on the freeway a lot), and 14.4v (if you mostly city drive the car). If it is already reading between those voltages, then you may have a weak connection at the generator, solenoid or control box.

Also, check that the battery voltage is at least 12.6v while sitting and engine not running. A cell can go bad and suck amperage from the generator.
 
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As usual, John has some great advice. While you're checking things, check all your ground connections dealing with the lighting circuits. Good time to remove and clean all of them. And let us know what you find.
 
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Thanks John and Mickey for your suggestions. All the voltages are close to what you recommended except I have to get to 3000 RPM to get 13.75 volts. I feel comfortable with those charging rates for daytime driving. When I turn the headlights on I get a steady 5 amp discharge, this is what troubles me. At 3000 RPM when I turn the lights on my battery voltage goes from 13.75 to 12.65 with -5 amps. My control box is about four years old and says WEHRLE on the cover. I don't believe it is adjustable or at least I don't know how to if it is. My connections seem to be OK.
Thanks,
TR3MT
 
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There's a procedure in the shop manual for adjusting the regulator. It's not difficult, so it might be a good idea just to go through it and make sure it's all correct. Also, make sure that the electrical contacts are clean and not burned. It's probably OK to clean them with a little fine sandpaper, but you can get a special file at an electronics place that is better. Also, a diamond-dust nail file is a good tool (Amazon) and might be easier to find.
 
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Did Standard use anything but Lucas voltage regulators? I don't recall seeing anything but the RB106 ones on TR-2 and 3. RB340 on later cars. Wehrle were on VW's and other German cars.
 
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13.75v is good, but not at 3000rpm. You should reach at least that by 1500rpm. I am also concerned that the voltage increases all the way to that point. Either the controller is not working correctly or the generator output is weak. You may be best advised to run the generator tests in the service manual. The steps will direct you to isolate the generator and test full output, and then work your way to the controller. They will help you isolate the problem to controller or generator.
 
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Thanks--I'll get into it a little deeper now and let you know.
 
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Where can I find the generator Test instructions? I am concerned that the generator my not have sufficient output if I am running at night and my cooling fan comes on. I am replacing most bulbs with LED but run an electric fuel pump and non-LED headlights. Max condition is cooling fan, headlights, and wipers all on at the same time. Would I be wise to get LED headlights? Does anyone know the generator amperage output limit?
Thanks for any info in advance.
 
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That's a different issue. You are using more power than the generator can supply. The generator is only rated from 19 to 21 amps. The headlights use at least 10 amps, the fan at least 10 amps, and the ignition about 3 amps. So, the bottom line is if you add an electric fan, you will need an alternator conversion.
 
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If originality is not an issue I highly recommend installing a British Wiring alternator kit. It puts out 65 amps. I installed a voltmeter gauge in the dash. Apparently there is even an alternator that looks just like the original generator that you can buy.
 
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Dunno specifically about the Moss product, but, in general, those kits are invariably an expensive version of something you can do on your own perfectly well. There are lots of descriptions in the archives here, and elsewhere on line.
 
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Another option is to keep the generator. As long as you don't run the car with full electrical load all the time, there should be time for the battery to recharge. You might get more efficient charging with an electronic regulator; some of them look just like the RB106 box. Or, use a battery maintainer. I use one regularly, even though my car's electrical system is stock. It will extend the life of the battery.
 
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If you install an alternator, get the one that's made in the UK, not an Asian country! I have an Chinese one under the bench that is only good for a door stop, as it hasn't worked after about 3 hours running! (n)
 
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