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Randy Roberson
Grand Master
Username: wascator

Post Number: 573
Registered: 5-2009
Posted on Monday, 30 November, 2015 - 08:21 am:   Edit PostDelete PostView Post/Check IP

An additional question while I am troubleshooting the suspected battery drain: Whenever the engine is running the ammeter needle swigs back and forth constantly and is never stationary. It is more toward the charge side when the engine is first started, then gradually moves back toward the neutral position but it is always in motion. One can see a slight flicker in the intensity of the interior lamps and head lamps which is in sync with this. Does this indicate a possible problem with the voltage regulator?
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Robert Noel Reddington
Grand Master
Username: bob_uk

Post Number: 771
Registered: 5-2015
Posted on Monday, 30 November, 2015 - 08:54 am:   Edit PostDelete PostView Post/Check IP

Usually its worn brushes in the alternator. These are accessed from the side of the alyernator and a complete strip down is not necessary.

The ammemter should after starter load and drain read on the plus side. Once battery has picked up a bit the reading should drop off and hover over the zero plus side showing less than 5 amps charge. If the lights are turned on the alternator should then balance the load. So apart from swing the alternator is behaving correctly.

The brushes supply the rotor field windings. The actual amount of power supplied to the rotor is regulated by the regulator. The power for the rotor comes from extra diodes inside the alternator. If these brushes are worn the power varies to the rotor when it shouldn't which causes ammeter swing.

The brushes are shown in the manual with the original length for comparison.
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Randy Roberson
Grand Master
Username: wascator

Post Number: 575
Registered: 5-2009
Posted on Monday, 30 November, 2015 - 09:10 am:   Edit PostDelete PostView Post/Check IP

Brushes: OK but my alternator just went through a repair shop of long standing and high repute. Also, this behavior was present prior to the rebuild and test.
The Ampere meter on the 1970 does not swing constantly.
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Jim Walters
Experienced User
Username: jim_walters

Post Number: 50
Registered: 1-2014
Posted on Monday, 30 November, 2015 - 01:44 pm:   Edit PostDelete PostView Post/Check IP

I'd say yes, it indicates the output is fluctuating and that could definitely be a symptom of a faulty regulator. Have you unplugged it while checking for your drain? Highly suspect IMHO.

SRE22493 NAC-05370
www.bristolmotors.com
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Randy Roberson
Grand Master
Username: wascator

Post Number: 577
Registered: 5-2009
Posted on Monday, 30 November, 2015 - 02:01 pm:   Edit PostDelete PostView Post/Check IP

Great info! I have not unplugged it YET (thanks). I remember the test process is described somewhere in the Manuals.
I verified all the interior bulbs including the red spots at the door jambs are going off when the system times out.
I did learn: removing the key from the ignition makes the same click as I was describing when connecting the ground cable. The drain at the ground goes to 35 mA when the key is removed. There is no audible buzzer as a "remove key" warning, and no lamps on at the dash. I also noticed the engine overheat warning which is supposed to light when activating the engine oil level check, does not light, so that bulb must be out as well. I will recheck all the warning panel lamps: I understand they all illuminate during cranking as a test; is this right? The Car typically starts so quickly I don't have much time to look. I replaced the fuel level sender which was in terrible shape, but no fuel gauge operation yet.
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Randy Roberson
Grand Master
Username: wascator

Post Number: 579
Registered: 5-2009
Posted on Monday, 30 November, 2015 - 02:39 pm:   Edit PostDelete PostView Post/Check IP

1. All warning lamps light on cranking: good.
2. Unplugging the leads to the regulator one at a time, at least one greatly reduces the drain.
Item 2, plus the constantly quivering Ampere meter needle, say "Dodgy voltage regulator".
3. I need a replacement lamp for the high beam indicator.
4. I don't know why leaving the key in the ignition causes a drain. I know I can leave it out easily enough, for now.
Thanks everyone!
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1033
Registered: 5-2012
Posted on Monday, 30 November, 2015 - 03:58 pm:   Edit PostDelete PostView Post/Check IP

Hi Randy

I replaced my regulator a couple of years ago but appear to have lost the name of the company. My car is an SY1 and the regulator was a C.A.V type 440D. The cost was less than $40. If your car has the same regulator a search of the web should find a comparable price. The headlights on my car remain at the same brightness whatever the revs. It certainly looks like a regulator issue.

Geoff
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Randy Roberson
Grand Master
Username: wascator

Post Number: 580
Registered: 5-2009
Posted on Tuesday, 01 December, 2015 - 12:46 am:   Edit PostDelete PostView Post/Check IP

I ordered one from FS very reasonable I thought.
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 1765
Registered: 6-2009
Posted on Tuesday, 01 December, 2015 - 02:02 am:   Edit PostDelete PostView Post/Check IP

Randy,

Also, regardless of what the owner's handbook or some other documentation might say, neither of my SY2 series cars has the engine overheat warning lamp illuminate when the oil level button is pressed.

I've only seen the full warning panel illuminate during the "crank test" when you are starting the car. I have had occasions where the crank test doesn't appear to function, but it does more times than it does not.

Brian
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Robert Noel Reddington
Grand Master
Username: bob_uk

Post Number: 772
Registered: 5-2015
Posted on Tuesday, 01 December, 2015 - 05:45 am:   Edit PostDelete PostView Post/Check IP

On some cars putting the key in and not turning it, that is the off position still controls some circuits.

My car SY 1 doesn't have an engine overheat warning light buzzer only and low coolant level light

The regulator at 40 bucks is cheap.

Mine was free of charge from Lucas service. Because they said it was faulty when it wasn't. It was the brushes in the alternator. Durite also do this regulator. It comes in 24v as well as 12v.

Put car in drive and operate starter will also light up the warning lamps with out the starter working