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Bugeye generator help

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ichthos

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My first successful trip today in my newly restored bugeye. I had to jump start it initially, but I expected that since it has been sitting for a couple months. No lights on during my half hour trip because I wanted to charge the battery, which is fairly new. When I shut off the car and tried to restart it, the battery had not charged enough to restart. Wouldn't this be a result of a bad generator? The belt tension is fine. I am not sure what else to check. I have a few questions I am hoping someone can help me out with:

1)How do I hook up a tester to check the output of the generator, and what should that output be? Please talk as simply as possible on how to do this.

2)Is there a person in my area (Olympia/Seattle)that rebuilds these or is there someone I can send this to to be rebuilt?

3)I want to have a back up generator, so I have thought about buying one. Is there someone who has purchased one lately that was happy with what they bought, and can you tell me who and how much?

Any help would greatly be appreciated.

Kevin
 
Kevin, assuming the generator output is the same as the alternator, you need a digital multimeter (under $10) set the voltage reading to 20 volts and lay across the battery terminals. If it is off, should read 11 - 12 volts, running should be 14.4 volts or so if charging.
 
Keven, you restored it so tell us what the white light in the spedo at the bottom does when ign on, enging not running and running?

My gen for example keeps Miss Agatha toped up just fine even with my limited driveing.
 
This is where an ammeter is really helpful, even if you don't install it permanently. Hook it up in series with the brown lead from the battery, and it will tell you if the thing is charging. You should get charge current when the engine speed is above about 1800 RPM.

If you're not charging, it could be the generator, but more likely is the control box. Everyone seems to assume that a bad generator is the cause of all charging problems, but more often it's the box.

Also, if you started with a flat battery, it might be a good idea to recharge it fully before driving, using a good-quality charger. That generator/control box combination is...let me see if I can remember the precise technical terminology...junk. Seriously, I am amazed that it works at all. It is marginally OK for keeping the battery charged, if you don't use the headlights too much, but very poor for recharging a discharged battery.

To check the voltage, I usually recommend an analog meter, not a digital multimeter. The car's electrical system generates a lot of voltage spikes, and these upset the digital meter. Not the analog ones, though.

You can check the generator by disconnecting the wires that go to it, then connecting the output to the field terminal. Start the car and keep it slow--like, below 2000 RPM. As you speed it up from idle, you should see the voltage rise to a good 20 volts or so. Don't go above this, or you could zap something. If this checks, and you still don't see charge current, almost certainly it's the control box.
 
Kevin,

Generators, unlike alternators, are not the best at "restoring" a low battery.

It's pretty simple to check the generator output (as mentioned above) and can be done in the car by disconnecting both the dynamo wires and clipping the two leads on the generator together with a jumper. Then, using a moving coil voltmeter, connect one lead of the meter to one of the generator terminals and other to the body of the dynamo to complete circuit to ground. Start the engine and let it idle. If you gradually increase idle, you should see a smooth voltage rise. You do not need to rev or exceed 1000-1500 RPM. Do not exceed 20 volts.

If that checks out fine, then you need to go through the procedure to check and adjust the control box (voltage regulator). The entire procedure for checking the charging system is outlined in the Bentley/shop manual.

John Twist of University Motors has also done some excellent how to videos on the subject.
 
I took both my starter and generator to Autozone to be tested before installation.
 
As did I with Miss Agatha. It was free and a nice escape from the garage.
 
Kevin, you are getting excellent advice and I don't want to get you offtrack, but I'm just wondering if you don't have some tiny load somewhere draining your battery. That's what I would be thinking if the battery was down after a couple of months. Shoot, out on the farm we might not crank something for six months at a time or even longer, and you just expect the battery will be up.

Jack asked several astute questions a few posts back (mine's a red light at the bottom of the speedo tho'). What's that little light doing?

Charlie
 
I am just now getting the chance to see all the replies - thanks. I will work backwards to answer questions. Charlie, I have a cut off switch, so I don't think it is draining anywhere.In reference to the ignition light, it goes on when I start the car (which I did tonight after trickle charging the battery for an hour), but the light goes off once the car is started. Ray, I may just end up taking your advice about taking the generator in to be checked. If the generator is good, then the most likely candidate would have to be the control box, correct? I am using the original control box and generator from when I bought the car. JP, I tested the battery as you instructed. I first tested the battery before I started the car and it read 12.54. I then tested it as the engine was running and it dropped to 12.45. Not sure if that is significant, and I am not sure if it would have dropped further had I kept the engine running. Gerard and Steve, I am sorry but I did not fully understand all that you were telling me, but I know I need to do some reading first.

So the bottom line is this, my battery does not seem to be charging if the voltage is supposed to go up slightly as JP suggested. This would mean that either the generator or control box are bad, correct? It seems like the most logical thing to do (with my understanding of electronics) would be to take in the generator to get it checked. If the generator checks out, it would have to be the control box, correct?

Kevin
 
Light is supose to go off when car is running, maybe 1500 rpm or there abouts.

That shows generator is working.

May I also suggest that generator and control box are working as advertised.


Time to run a test. Will the battery hold a charge and for how many days. Use the car and keep an eye on it.

Report findings here.

I suggest bad battery.
 
OK, I'll do as you suggest. I will let it sit for a week with the cutoff switch turned off. The battery is new, but it wouldn't be the first time a new part was bad. My only questions is shouldn't the voltage go up slightly though when the car is running?
Kevin
 
Based on your voltage checks, the generator/control box combo is not charging the battery. I have never been successful just changing out either the generator or the control box alone, as even most suppliers recommend changing both. I would take the Gen off and have it tested alone. If that is good, then it is the control box. I switched my control box over to an electronic one, as I have never had a "good" relationship with the Lucas charging systems. Probably, nothing to lose, except the generator, to buy a new control box and try it out with the existing checked out generator.
If you look at the manual for the the control box, it is not the easiest thing to understand.
Good luck. Scott in CA
 
Kevin,

There are several adjustments to the control box, so I don't agree that "replacing" is necessarily the solution. If the generator is good, then it may just be a matter of setting the limits on the relays correctly. All that takes is a multimeter and a screwdriver. It could also be a polarization issue, and that should be done first anyway, especially if you remove the generator from the car to be tested. I have on many occasions corrected the problems you describe via polarization and/or following the control box adjustment procedure. I think I'd spring for a good (Bentley) shop manual, if you don't have one, rather than replacing all your electrical stuff as an "experiment".
 
I was just looking through the Moss catalog and noticed there are two prices for the regulator - one that is tested and adjusted, and one that is not. I didn't know what they were talking about until you posted, Gerard. Is this something easy to do? Probably good advice on the Bentley manual. I have one for my TR6, but didn't know he wrote one for the Bugeye. Who sells them? By the way, if the generator is not polarized, what would the effect be on the charging?
Kevin
 
Kevin,
The MGA guru site has a diagnostics document for a Lucas control box here: Lucas control box tests. Not 100% sure that this is for your car's box but it will be informative.

Do try Jack's suggestion. Bad batteries are sure not unheard of even in this day and age, however. I had one a couple of years ago. It would charge up on the charger in just a few hours, then be discharged a few hours later. I was convinced I had a phantom load somewhere. I just could not accept that this brand new battery was bad, eventually took it back to the store and it sure was bad.

But I am voting control box needs adjusting.

I suspect the reason Moss has cleaned and tested units, as well as uncleaned units that need adjusting, is that these are NLA and you are getting a used box. Perhaps the uncleaned units are mainly for looks only?

Charlie

BTW I think you are correctly polarized. Your generator would not be putting the little light on the speedo out if you weren't. If you have not have had the generator out of the car for a lengthy period of time it should be fine.

To polarize simply take a wire and momentarily touch the A and F terminals on your control box together just a second. You will get a little spark and you're done.
 
If I am correctly polarized, and I touch the wires again to make sure, what will happen? Checked my battery, and it dropped from 12.42 to 12.32 overnight. Is this significant? Either way, I know it is not charging. I am getting over run by work, but I will try and go through everything you guys have suggested I read and get back. Thanks for all the help.
 
Kevin, you can polarize as many times as you like. It will neither hurt or improve things.

I'm not sure whether .1 of a volt is significant or not, but yes, if you are losing a .1 of a volt every day, well, do the math! Keep an eye on it.

I know you said you have a battery cutoff switch on there, but I have been burned many times because I did not check the obvious. Occam's Razor, eh? So if you want to easily take the question of whether there is some tiny load draining your battery out of the list of possibilities, remove the positive cable from your battery and put an ammeter between the battery positive terminal and positive battery cable you just took off.

Oh, those instructions presume you have a negative ground car. If you are positive ground do everything I said except you are measuring between the negative battery terminal and the negative battery cable.

You will get a reading if any current is flowing. You would be talking about milliamps here. BTW, your multimeter may or may not have an ammeter function, the cheapest ones don't. You are trying to measure amps.

Good luck
Charlie
 
Battery voltage will vary with temperature.
 
Agree on polarizing and suspect you are correct.

Did you not put in a new regulator when you restored the car?
 
Just to make sure, the control box is the same as the regulator, correct? In any case, no, I did not replace it. I didn't see anything corroded or damaged, so I reused it. This car has one big learning experience for me. What I did was test/inspect items as I installed them, at least for the pieces I knew <span style="font-weight: bold"><span style="font-style: italic">how </span></span>to test. Is this something that is routinely replaced?

Trevor, it was quite a bit colder when I checked it the second time. I will check again tonight and contiue to monitor the battery.

Charlie, if it keeps dropping I will set things up like you suggested. I know it is a long shot, but I will repolarize again tonight.

I think I need to still do some reading to learn how to make adjustments with the control box. I am taking in the generator tomorrow to get checked.

Kevin
 
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