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Complete charging system failure


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The Grey Lady and I just returned from "The Gathering", an annual event set in the rolling hills of northern NC. This was the Lady's first long distance trip at something less than 1500 miles round trip. See posting in Main Forum with link to photos.

 

During the second day the IGN light suddenly lit. It was not a flicker. It was easily noticeable in full daylight. I should explain that due to intermittent heavy showers and cool temperatures, I was running with full head lamps, heater/fan and GPS/cell phone charger. Needless to say my little Lucas generator was hard pressed anyway. I managed through the weekend by charging the battery each night. A full charge and judicious use of lights, heater, etc. got me through the day. I left for home early Sunday morning with a full charge and brilliant sunlight so headlamps were not required. However, I was somewhat anxious of the 600 mile trip before me. I realized that the ignition system did have a minimum voltage cutoff. Was it possible to male it home before the sparks stopped jumping across my vintage Lodge plugs?

 

Two more stops - one for fuel - and a second for biological needs (I'm now 65 years old). During the second stop, I had to turn off the engine due to security. When I attempted to re-start the engine the battery was so low it could not turn the starter. Fortunately some local chaps gave me a push and I got started.

 

Fast Forward - I finally arrived home at 5pm. I was dam curious! So I got the digital voltmeter and measured the battery voltage . . . . . . . . 5.86 volts - AND during the final 20 miles there was a distinct loss in power, no doubt, due to reduced spark voltage. So, there it is, empirically established that the minimum ignition voltage is something perhaps in the range of 5 - 5.5 volts, depending on many factors like temp, compression ratio, etc.

 

Epilogue: The failure was due to a bad resistor on the printed circuit board in the solid state voltage regulator.

 

http://i135.photobucket.com/albums/q159/angelfj/My_installation_1_DSC07015.jpg

 

I spoke to Bob at Wilton Auto Electric this morning. He said that he has determined that the resistor in question only overheats on long trips, more than 3 hours or so. He was happy to offer a quick turn-around on an upgrade. Until the unit is returned I will use my old Lucas unit. Isn't that ironic!!!

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I just installed a solid state voltage regulator from Wilton. Do all his regulators have this problem. I will be using the car for long trips so perhaps I should send mine in also. By upgrade do you mean one that will work for more than 3 hours at a time?

Robert

Edited by tr3aproj
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My Bentley has the original R-R Lucas regulator on it,,which needed its contacts cleaning and re-adjusting when I got it fifteen years ago and it's been alright since. It may not have needed attention if it hadn't been laid up for twenty years in the Arizona desert. Point is that it's sixty two years old now and still working fine, so why would I want a solid state one.

 

It's the same as the one on my TR and Ive got a brand new spare, but the TR didn't need it either. It has a very old looking one on it too, but I had to buy a new dynamo for £27, which was a bit depressing.

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Hi Frank,

I am with Ash on this one. What was your reason for going to solid state and particularly on a sidescreen where the scuttle shake is commonly known? I am really interested in the answer.

What you have is a thinly disguised fake or ersatz unit which possibly has vibration issues centred around the constant for 1000's of miles.

 

When restoring a TR with Lucas electrics you must ensure that you fill the Lucas black smoke box that is characteristicfor the period.

Personally I would go back to a rebuilt Lucas regulator and an uprated Dynamo for originality and wait till the unit is proved to be reliable. I have an original regulator and a 35amp dynamo which seems to be more than adequate for all my needs.

If you want or need a lucas smoke box let me know as I have two or three spares. The best information is that the rebuilt original is the best way as repro ones are not built with the quality of the "old" material.

Cox automotive are consideredto be "old school" and rebuild this stuff routinely.

http://www.coxautomotive.co.uk/supports.html

 

 

Rgds

Rod

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I appreciate the discussion and I would be a hypocrite if I suggested that I had no concern for originality, which was as most of you that have followed my trials and tribulations, the main theme of my restoration project

 

I was attracted by the Bob Jeffers, Wilton Auto Electric design because it was a do once and forget improvement. It has the added benefit of stealth and can not be discovered by concours judges. Conversely, I was frustrated by the difficulty in keeping the original Lucas box in proper adjustment. Anyone who has followed the Lucas documentation can appreciate what I am stating.

 

To be fair to any regulating system either solid state or electromechanical, my Lucas generator was subjected to almost constant overload during this recent trip. Even a wide-open regulator can not compensate for an inadequate electrical source. With, heater fan, headlights and windscreen wipers running simultaneously, now add the enhancements I made for safety. I have added an extra brake light (incandescent) which attaches by magnets to the surface of the boot lid, just below the fuel filler. We also changed the wiring so that when you step on the brake, five rear lamps lite, that is, tail lamps x 2 + indicators x 2 + new extra brake light. These lights are all incandescent. Another change has both the tail lights and indicators flashing when making turns. We also now have true 4-way emergency flashers. In an emergency, I can flip a small toggle switch to activate the flashers. Then everything flashes, front and rear indicators and brake lights. Except for the emergency flashers which I only used once for about 10 minutes, I was constantly using other new features thus taxing the regulator , generator and battery.

 

To be fair to Bob Jeffers, he only recently became aware of the resistor problem in his solid state design. I suppose that most drivers using his system don't drive over 3 - 4 hours at a time but rather take their cars out for an afternoon of spirited motoring down the highway. I am anxious to get my solid state unit back from Bob. When I do, I'll provide a follow-up to this post. :)

 

Cheers, Frank

 

 

 

 

.

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Hi Frank,

I am with Ash on this one. What was your reason for going to solid state and particularly on a sidescreen where the scuttle shake is commonly known? I am really interested in the answer.

What you have is a thinly disguised fake or ersatz unit which possibly has vibration issues centred around the constant for 1000's of miles.

 

When restoring a TR with Lucas electrics you must ensure that you fill the Lucas black smoke box that is characteristicfor the period.

Personally I would go back to a rebuilt Lucas regulator and an uprated Dynamo for originality and wait till the unit is proved to be reliable. I have an original regulator and a 35amp dynamo which seems to be more than adequate for all my needs.

If you want or need a lucas smoke box let me know as I have two or three spares. The best information is that the rebuilt original is the best way as repro ones are not built with the quality of the "old" material.

Cox automotive are consideredto be "old school" and rebuild this stuff routinely.

http://www.coxautomotive.co.uk/supports.html

 

 

Rgds

Rod

Tell me Rod, as I am not aware of a 35 amp Lucas generator that would fit a 1959 TR3A. The standard unit produces maybe 18 amps!

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Frank, knowing how unreliable repro voltage regulators have been, I thought the electronic upgrade was a good idea, especially being undetectable inside the Lucas case. I would have fitted one to my car, except for having installed a NOS original regulator just before they were released.

 

Anyhow, after your trip, it's good the heat prone resistor has come to light and users will benefit from improved reliability.

Although more costly, perhaps military specification components would help ?. I once had milspec diodes put in a troublesome Lucas alternator, ending flat batteries on that car once and for all.

Regards,

Viv.

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Hi Frank,

Company Is London and Essex Auto Electricas Ltd.

ebay item 281092522551

 

Only difference is the post that exits from the body rather than the end its further away from the exhaust.

Typically used on Ice cream Vans for the fridges and PA system.

Works for me with original Lucas regulator but not for the dedicated Concours enthuisiast maybe?

rgds

Rod

 

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According to my technical documentation the standard Lucas generator on the TR3A was Model C 39 PV2 22258 which generated a maximum of 19 Amps and 13.5 volts at 2150 rpm.

 

Ok I am just showing off as I managed to bag a 47 page French technical publication on the 3A at a car boot this weekend for 5 euros

(RTA August 1961)

 

Cheers

 

Alan

Edited by Kiwifrog
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Hi Frank,

Company Is London and Essex Auto Electricas Ltd.

ebay item 281092522551

 

Only difference is the post that exits from the body rather than the end its further away from the exhaust.

Typically used on Ice cream Vans for the fridges and PA system.

Works for me with original Lucas regulator but not for the dedicated Concours enthuisiast maybe?

rgds

Rod

 

Many thanks! I will definitely check this out!

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Hi Frank,

Or you could look at this Ebay item 390546105048

The dynamator looks like the generator and fits exactly the same.

 

I am not sure what you mean by "Conversely, I was frustrated by the difficulty in keeping the original Lucas box in proper adjustment."

 

More knowledgable people than me would have an opinion on the rquirement for constant adjustment of the voltage regulator. What was the issue that required constant adjustment bearing in mind that all and any adjustments need to be done within 30 seconds as the heat build in the coils and springs will alter settings?

 

Best regards

Rod

 

 

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Hi Frank

Concerning the regulator the general advice is to NEVER open the damned thing. I have followed this advice to the letter on my TR2, mainly because it has behaved impeccably over 22+ years, and is maybe the original one as well.

Having said that if it were to go wrong I would think seriously about a solid state mod, has to be the "way to go".

cheers

Colin

p.s. I am currently having troubles with the indicator relay, put a new one in a week ago and it stopped working sunday for our uk "drive-it-day". Anyone know of a source for proper ones, that will last longer than 3 miles and two turns? It's positive earth and screw threaded wire fixing holes.

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Repro glass fuses can be a problem as they can appear to be complete but are not properly soldered at one or both ends. Been there done that,

Best always to check with a meter and keep at least a couple of spares in the glove box.

An easy fix and cheap to.

Rgds

Rod

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  • 2 weeks later...

New Development! I returned my Wilton Auto Electric control box late last week. Got an email from Bob Jeffers yesterday stating that he has tested the solid state regulator unit and it is working perfectly! Bob suggests that it was the dynamo all along.

We found a spare C39PV2 dynamo.
Using jumper leads, we connected this to the car as a substitute to the in situ one.
Flashed the field.
With everything connected and ready, switched on the IGN.
Red light came on which is correct.
Using a heavy duty electric drill, we spun up the spare dynamo and the red light went out.
This indicates that the spare dynamo is OK and the spare original style control box is OK.

So friends, I was fooled into believing that the solid state control box caused the charging system to fail.
Hat's off to Bob Jeffers for his advice and solid product.

Tonight we replace the bad dynamo.

In a few days I hope to report on the autopsy of the failed unit. The field coils tested OK so I suspect a bad armature.

Stay tuned.

Frank

 

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:rolleyes:

 

Well we spent a couple of hours Thursday evening removing the failed generator and installing the backup. The backup runs great.

 

As far as the bad one goes, the armature got completely toasted and roasted. The copper winding got so hot that the insulation is burned black! The silver solder which connect the windings to the commutator got so hot that they melted producing a solder ring around the inside of the yoke.

 

The shaft has a distinct wobble and I believe the rear bushing failed because it was not properly oiled. The hole in the bushing is now egg shaped and that end of the shaft is not round anymore!

 

The unit was serviced by an auto electric shop a few years ago and put in storage until we needed it. Our theory is that they forgot to soak the 'oilite' bronze bushing in oil prior to installing it. This caused premature bushing failure and subsequent failure of the commutator, arcing, high temp, ect, etc. Too bad because this particular shop had done several dynamos and starters with excellent results. Note: The replacement armature came with a steel replacement bushing. We do not intend to use this and will fit a proper 'oilite' bronze type.

 

This failure spared the field coils which measure in spec at 6.1 ohms. I meggered (500 volt) the windings to earth and they pass.

 

Obtained a new armature (Lucas India) plus bushing and brushes from Moss USA to put in this unit and use for a spare.

 

Additional thoughts: The suspect solid state regulator was a red herring. There was never anything wrong with it. It was returned to Wilton who tested it and verified it and OK. A clarification is in order. When I first ordered the unit I made an error in describing my dynamo as a C40. This resulted in a current limit setting of 22 amps. The C39 has a maximum capacity of 19 amps. Thus the regulator allowed a 16 percent overload which probably helped to cook the unit

 

 

Here are some photos.

 

C39PV2DynamoFailure-R1.jpg

 

C39PV2DynamoFailure-3-R1.jpg

 

 

C39PV2DynamoFailure-8-R1.jpg

 

 

C39PV2DynamoFailure-2-R1.jpg

 

 

C39PV2DynamoFailure-11-R1.jpg

Edited by angelfj
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Frank, your bearing failure could be from an over tight belt, woulden't be the first time?

Graham

Graham: Your correct for sure and that was the first thing we checked. Our belt was in proper form.

 

Cheers

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Can someone educate me on the proper oiling of the generator? I am using the original generator and control box (rebuilt at the same time by Cox) and it has worked fine ever since the rebuild. I have no ancillaries other than standard ones, and no heater. But when would the need for oiling arise after a rebuild?

 

Cheers

 

Dan

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Can someone educate me on the proper oiling of the generator? I am using the original generator and control box (rebuilt at the same time by Cox) and it has worked fine ever since the rebuild. I have no ancillaries other than standard ones, and no heater. But when would the need for oiling arise after a rebuild?

 

Cheers

 

Dan

 

lube.jpg

 

 

 

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