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TR2/3/3A Rebuild generator or go w/ alternator for TR3a
- Thread starter tdskip
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D
DougF
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Looks like a very nice solid, straight car. It should be a lot of fun.
It would depend on what type of driving you're planning.
For a lot of long distance travels, I would go with the alternator.
For local driving, I would stay original.
It would depend on what type of driving you're planning.
For a lot of long distance travels, I would go with the alternator.
For local driving, I would stay original.
martx-5
Yoda
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It might not be the generator. It could be the voltage regulator. My service manual has a procedure to determine if the generator is faulty...
Switch off all lights and accesories, disconnect the cables from the generator and connect the terminals with a short length of wire. Start the engine and run at normal idleing speed. Clip the negative lead of a voltmeter to one of the generator terminals, and the other to ground. Gradually increase the engine speed, when the voltmeter reading should rise rapidly and without fluctuation. Do not allow the voltmeter reading to reach 20 volts and do not race engine in an attempt to increase the voltage. It is sufficient to run the generator up to 1,000 rpm.
If there is no reading, brushes may be the problem. A low reading of 1/2-1 volt, the field winding may be at fault. If the reading is about 6-7 volts, the armature may be at fault. If the generator is good, then you will see the higher voltages (12-20) according to engine speed.
Find out what is wrong first, then you can better decide what you want to replace with what.
Switch off all lights and accesories, disconnect the cables from the generator and connect the terminals with a short length of wire. Start the engine and run at normal idleing speed. Clip the negative lead of a voltmeter to one of the generator terminals, and the other to ground. Gradually increase the engine speed, when the voltmeter reading should rise rapidly and without fluctuation. Do not allow the voltmeter reading to reach 20 volts and do not race engine in an attempt to increase the voltage. It is sufficient to run the generator up to 1,000 rpm.
If there is no reading, brushes may be the problem. A low reading of 1/2-1 volt, the field winding may be at fault. If the reading is about 6-7 volts, the armature may be at fault. If the generator is good, then you will see the higher voltages (12-20) according to engine speed.
Find out what is wrong first, then you can better decide what you want to replace with what.
DougF said:
Doug, what's the rationale behind that? I've driven many, many, thousands of miles with generator equipped cars, and can only recall one problem, easily fixed beside the road. Generators function perfectly fine, as long as you don't install a lot of high load accessories.
Jeff
2wrench
Luke Skywalker
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Stay orig my opinion. Why? You know what you got.
You'll never be plagued with wondering, down the
road, if any other electrical issues are a chicken
or the egg problem.
Rebuilt properly functioning generator? Likely with
a elec prob, you can look elsewhere without
looking over your shoulder.
Just in my humble opinion.
You'll never be plagued with wondering, down the
road, if any other electrical issues are a chicken
or the egg problem.
Rebuilt properly functioning generator? Likely with
a elec prob, you can look elsewhere without
looking over your shoulder.
Just in my humble opinion.
D
DougF
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My rationale was exactly that, to take care of the high load components that might go on the long trips.
D
DougF
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It would probably be easier and cheaper to carry a spare.
bluemiata90
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tdskip, you almost answered you own question. As stated by several other posters, if your not going to run a new stereo or upgraded lights, I'd stay original and have it rebuilt. I on the other hand, installed a new stereo and added blue lights and a fog light bar on mine, so the grounding had to be changed and a newer delco alt. had to be installed. The conversion was truly very simple and actually cheaper then having my generator rebuilt.
PeterK
Yoda
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It's good to see a TR3 that is not red (like ours). Very nice color and looks like a great driver.
I switched to an alternator after my generator popped loudly and spit out some kind of wadding.
I was already running sealed beam halogens but now run H4s -nice and bright!) Also for us, a hidden radio by Custom Autosound, electric fan, and a couple of other elec devices. The stock generator puts out around 20-something amps, and the Delco alternator put out 63. Plenty of juice, cheap to replace and an easy install. And if you every do want to add some Oscars to the front, you'll have the power. Did I mention, no regulator is needed either?
I switched to an alternator after my generator popped loudly and spit out some kind of wadding.
I was already running sealed beam halogens but now run H4s -nice and bright!) Also for us, a hidden radio by Custom Autosound, electric fan, and a couple of other elec devices. The stock generator puts out around 20-something amps, and the Delco alternator put out 63. Plenty of juice, cheap to replace and an easy install. And if you every do want to add some Oscars to the front, you'll have the power. Did I mention, no regulator is needed either?
tomshobby
Yoda
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Once upon a time when all there were only generator we did not think there was anything wrong when the engine RPM's slowed and the lights went dim because the voltage output dropped.
When more and more demands were put on the electrical system it became more problematic. One big difference is that at idle a generator voltage output will drop enough that the battery will be discharging until the RPM's are increased again.
With an alternator, if all accessories are off, it will charge at an idle because it will have full voltage. At least that is the theory and not how my Lucas alternator seems to work although my GM alternators did.
When more and more demands were put on the electrical system it became more problematic. One big difference is that at idle a generator voltage output will drop enough that the battery will be discharging until the RPM's are increased again.
With an alternator, if all accessories are off, it will charge at an idle because it will have full voltage. At least that is the theory and not how my Lucas alternator seems to work although my GM alternators did.
martx-5
Yoda
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The GM alternators you were using were probably the 63 amp 10 SI. That still a far cry from the early Lucas alternators that put out about 35 amps. Alternators will put out anywhere between 30-50% of their rated output at idle. So, in the case of a TR3's 20 amp rated generator, that 10 SI GM unit can put that much out at idle.
Also, as a point of interest (or you can stop reading if you're not interested), when alternators are 'modified' to put out more amperage, very often the 'Y' wound stator is replaced with a 'Delta' wound stator. That will increase the output of any alternator, but low speed performance always suffers. Therefore, the new high amp alternator most likely will not put out as much at idle as the original 'Y' wound stator. What OE manufacurer's have discovered over the last 8-10 years, is that by rectifying the connector in a 'Y' wound stator, the total output will increase by about 5-10%, but still retain high low speed output. These alternators have eight diodes in them instead of the normal six.
Are you bored?? Ok, I'll shut up!
Also, as a point of interest (or you can stop reading if you're not interested), when alternators are 'modified' to put out more amperage, very often the 'Y' wound stator is replaced with a 'Delta' wound stator. That will increase the output of any alternator, but low speed performance always suffers. Therefore, the new high amp alternator most likely will not put out as much at idle as the original 'Y' wound stator. What OE manufacurer's have discovered over the last 8-10 years, is that by rectifying the connector in a 'Y' wound stator, the total output will increase by about 5-10%, but still retain high low speed output. These alternators have eight diodes in them instead of the normal six.
Are you bored?? Ok, I'll shut up!
TR3driver
Great Pumpkin - R.I.P
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FWIW, I think generators are frequently blamed for what turn out to be control box problems.
One issue is that the generator will easily put out more than it's rated output current, which will overheat and damage it. It's the control box's responsibility to limit the generator output to either 19 or 21 amps (depending on whether you have an original TR2-3 generator or the later, slightly larger unit from a TR4). If the control box is not properly adjusted (as it seems many of them are not, even right out of the box), it can allow the generator to overheat and eventually destroy itself. In extreme cases, you can see the thrown solder, but a slight overheat just cooks the winding insulation and causes it to fail prematurely.
A short in the wires between control box & generator can cause the same symptom.
One issue is that the generator will easily put out more than it's rated output current, which will overheat and damage it. It's the control box's responsibility to limit the generator output to either 19 or 21 amps (depending on whether you have an original TR2-3 generator or the later, slightly larger unit from a TR4). If the control box is not properly adjusted (as it seems many of them are not, even right out of the box), it can allow the generator to overheat and eventually destroy itself. In extreme cases, you can see the thrown solder, but a slight overheat just cooks the winding insulation and causes it to fail prematurely.
A short in the wires between control box & generator can cause the same symptom.