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TR2/3/3A Voltage Regulator and Charging issues

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Frank_D

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Ok; I need some insight from the wise TR gentlemen about my charging system on TS42756L. I have a newly re-built CR39 generator installed and working well (I think), a new Voltage Regulator from Moss (cleaned and adjusted) a new battery. I am about to store for the winter and have set up my battery tender which brought the battery right up to about 13.6 volts (hand held digital voltmeter). Took the TR for a run this afternoon and on start up ammeter was deflecting well to the positive and the dash monunted voltmeter (aftermarket unit) was showing about 13.8 volts. All OK.

Drove for about 20 miles at 60 MPH with headlights on for a period and then with them off. As I drove, ammeter move to zero deflection and voltmeter indicated 12 volts. After about 5 more miles at speed, ammeter was in the negative, and dash mounted voltmeter was less than 12 volts. Carried on for a while like this and then pulled up in front of the house and idled at about 1200 RPM at which time the ammeter moved back into the positive and voltmeter showed about 12.4 volts. After shutdown my digital had held voltmeter showed battery at 12.7 volts.

Why would my ammeter have been in the negative and voltmeter at less than 12 volts when I was at 3000 RPM and 60 MPH? No lights on at the time.

Confused or not aware how it should be? Thanks fellows.

FD
 
One possibility would be oil or something on the regulator contacts, that kept them from making good contact. Another might be a bad connection at some point, that opened up while you were driving and then closed again.

Ammeter negative at 3000 rpm is definitely not normal, unless you have more than the standard load connected (eg electric radiator fan or high power stereo).

If you start it now and run at fast idle, does the ammeter go to roughly +15 amps and stay there? If so, I'd say the problem is intermittent (which will make troubleshooting difficult).
 
Belt slip is possible. Wrong belt (too narrow) bottoming out, oil or antifreeze on belt.
Check tension with your finger (engine off, keys in pocket) then hook your finger around belt and pull up. Now check your finger for any deposits that might be on the belt.
 
Frank D. This is not a easy thing to find. I'm sure you will check all the usual suspects, but here is one that has happened to cars I've worked on over the past 50 years. The new generator brushes would lift off the armature at higher RPM's until they were seated and cause exactly what you are experiencing.
Just a thought.

Wayne
 
Good advice all around folks. Wayne, your suggestion may very well be an issue to look at. Never would have suspected that. I will look at all of these and go from there. May not get a road test before they start salting the roads around here. Too bad I cant take the TR to FLA with me for the winter. Stay tuned.

Frank D....
 
Frank D, OK, now your poor car is going in a cold garage and you are heading to FL. Every heard of a ULTALITE. A trailer that weights nothing, surely driving all winter in the TR would be worth it.

Wayne
 
Thank you for the link to the manual. It is a great reference and I will put it to good use. Today I did a short drive of about 20 miles but with my old VR re-installed. I had cleaned the contacts and checked the gap etc. Drive was fine but system still not charging well. I thought I would try the most simple test of the dynamo; with car at idle (1200 RPM) I switched the battery off then switched on heater fan, wipers, side lights and finally the brake lights. At that point the car stalled. So without even using a meter, it is apparent that my so called re-built Lucas C39 dynamo is not producing enough to run the car and those basic electrical demands. I know where to look now. Thanks to all for helping with my education and issues.

Frank D........
 
Frank,

If you need a lend of a generator to help problem solve, (or extend your driving season) I have one ready to go in the spares box. Yours until the Spring if need be !

Cheers
Tush
 
Even my "healthy" C39 won't keep up with a full load at only 1200 engine rpm, so I'm not convinced your test means anything. The system normally runs on the battery at low rpm.

Here's a slightly more concise manual (although I think it is basically the same information):
https://drive.google.com/file/d/0B2...NDNmLWI0YTYtNjY5ZjQxZTA2NGFm/view?usp=sharing

Just as a side comment, I noticed the ammeter acting a little flaky yesterday (in heavy traffic with headlights and radiator fan both on), so I cleaned the regulator contacts this morning. Result was no charge at all! Not sure what happened, but I had to back off the gap adjustment and run a burnishing tool (aka point file) over them to get them working again. Afterwards, the voltage adjustment was way off, so I had to tweak that up again as well.
 
Thanks Tush. I am pretty much parked until spring. Will solve this by then. Thanks also Randall because you are as usual right about dyno power at 1200 RPM. Not thinking on that note. I was surprised by your issues yesterday. I am going to go through the the processes in the manuals provided before I do antying else. Thanks to all

Frank D....
 
trrdster2000 said:
Frank D, OK, now your poor car is going in a cold garage and you are heading to FL. Every heard of a ULTALITE. A trailer that weights nothing, surely driving all winter in the TR would be worth it.

Wayne
Click to expand...
Do you have any more information, maybe a description of what it is? Google didn't seem to come up with anything that would help in transporting a TR3.

Although I drive my TR3 all the time, I would like to have a trailer so I could transport it and family to TRfest (for example). Dad isn't used to LA traffic and his eyesight isn't what it used to be (neither is mine, come to that), so a small trailer would come in handy.
 
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