halcyon
Well-Known Member
The coil / relay looks like the suppression unit, only takes out spikes so should not affect warning light.
Down to continuity and regulator test, you can also vary the regulator voltage, hi, med and low.
Brian
Lucas Regulator and/or Relay Problem
- Thread starter Graham Pearson
- Start date
The coil / relay looks like the suppression unit, only takes out spikes so should not affect warning light.
Down to continuity and regulator test, you can also vary the regulator voltage, hi, med and low.
Brian
nigelmercier
RIP
- Joined
- 20 Jun 2007
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- 16,234
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- Live in Kent, boat in Canary Islands
Well, if there is a relay or a lamp in that circuit diagram, I can't see it.
bixter
New Member
the relay is for surge protection if the voltage is too high the zener diode conducts, closing the relay , connecting the "A" terminal to the negative hence reducing the field current to zero and stopping the alternator charging.
if the light comes on when you push the relay you need to check that there is negative at the "F" terminal ( the small one at the right hand side going to the aternator) If there is negative there then there is a problem with the alternator field circuit either a broken wire or brushes
if the light comes on when you push the relay you need to check that there is negative at the "F" terminal ( the small one at the right hand side going to the aternator) If there is negative there then there is a problem with the alternator field circuit either a broken wire or brushes
NorthUp
Well-Known Member
The lamp is bottom left, labeled 'WL'.
The type 448 fuse was external to the steel control box- they were hidden under a black bakelite type cover, with a spare fuse mounted alongside.
These control boxes are prone to several faults, including the failure of the solder joints where the 'coils' are joined under the regulator.
The surge supression board also gives problems with bad connections.
If you disconnect the regulator, connect the F(ield) wire to neg, and A to positive, briefly, the alternator will charge at full voltage and more if the rest of the box is ok. If not charging then bypass the entire box, ie connect battery pos/ neg to the alternator pos/neg and try again.
If still no charge suspect the alternator itself.
On more than one occasion I have discarded the surge supression- bypassed it, and substituted a couple of 80A forklift type fuses (RS components) for limited protection.
All the above at your own risk of course!
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William_H
Well-Known Member
I would suggest that if you are having problems with charging then it is the fault of the alternator specifically the brushes are worn so failing to conduct field current to the rotor. The brushes are usually easily removed via a small plate or box that holds the brushes. You can then examine the slip rings for condition. Black and burnt means bad contacts.
regarding the wiring diagram. This appears to be quite a sophisticated system designed for floating negative. ie negative insulated from engine block and water. The box on the left with 2 heavy coils and one lighter coil. Are simply isolating inductors which coupled with feed through capacitors at the bottom of the box symbol are designed to reduce radio interference. They will not affect the actual operating of the system.
The relay as you call it is a device apparently connected across from the field coil +ve connections to the alternator negative. The zener didoe is that diode with funny legs on it. It conducts in reverse direction when a given voltage is exceeded. This conducts current through one coil of the relay causing it to operate. In operating it connects an additional coil to increase relay current so locking the relay operated. This bypasses or shorts out the alternator filed coil so stopping charging. I presume this is to protect the system from full 24v on the field so protecting the system from a full charge situation. I can only suggest this might happen if the regulator fails in short circuit mode. Normal operation can only be resumed by turning off ignition and or stopping engine so relay releases.
Now back in early days of transistors it was difficult to make transistors tolerant to high voltages and the failure mode was almost always short circuit internally. More recently high voltage tolerant transistors are cheaper and more common so failure is much less likely. (Nb this is a 24 volt system sop voltage are much higher)
So breaking it all down you could ignore or even remove the relay and its associated zener diode. (just disconnect.) if however the old regulator were to fail you could end up with high charging voltage damaged electrics and cooked battery. A new regulator would be much more reliable we would hope. Like wise the box i it is separate that has the suppressor devices in could be removed but no point.
As far as I can see the basic circuit is normal batt +ve through ignitions witch to warning light to regulator. from regulator to field coils (rotor) then back to (possibly) the common negative. It is not clear if the regulator is a so called pos or neg regulation as wiring goes into the reg then to the field coil and back to regulator. Light should come on with ign on engine stopped and go out when alternator starts charging so supplying its own power for field current. Of course I may be wrong in some or all aspectw of this diatribe. good luck olewill
regarding the wiring diagram. This appears to be quite a sophisticated system designed for floating negative. ie negative insulated from engine block and water. The box on the left with 2 heavy coils and one lighter coil. Are simply isolating inductors which coupled with feed through capacitors at the bottom of the box symbol are designed to reduce radio interference. They will not affect the actual operating of the system.
The relay as you call it is a device apparently connected across from the field coil +ve connections to the alternator negative. The zener didoe is that diode with funny legs on it. It conducts in reverse direction when a given voltage is exceeded. This conducts current through one coil of the relay causing it to operate. In operating it connects an additional coil to increase relay current so locking the relay operated. This bypasses or shorts out the alternator filed coil so stopping charging. I presume this is to protect the system from full 24v on the field so protecting the system from a full charge situation. I can only suggest this might happen if the regulator fails in short circuit mode. Normal operation can only be resumed by turning off ignition and or stopping engine so relay releases.
Now back in early days of transistors it was difficult to make transistors tolerant to high voltages and the failure mode was almost always short circuit internally. More recently high voltage tolerant transistors are cheaper and more common so failure is much less likely. (Nb this is a 24 volt system sop voltage are much higher)
So breaking it all down you could ignore or even remove the relay and its associated zener diode. (just disconnect.) if however the old regulator were to fail you could end up with high charging voltage damaged electrics and cooked battery. A new regulator would be much more reliable we would hope. Like wise the box i it is separate that has the suppressor devices in could be removed but no point.
As far as I can see the basic circuit is normal batt +ve through ignitions witch to warning light to regulator. from regulator to field coils (rotor) then back to (possibly) the common negative. It is not clear if the regulator is a so called pos or neg regulation as wiring goes into the reg then to the field coil and back to regulator. Light should come on with ign on engine stopped and go out when alternator starts charging so supplying its own power for field current. Of course I may be wrong in some or all aspectw of this diatribe. good luck olewill
Last edited:
nigelmercier
RIP
- Joined
- 20 Jun 2007
- Messages
- 16,234
- Location
- Live in Kent, boat in Canary Islands
I did wonder about that, couldn't see the "W". But where is the relay? I'm guessing the contacts are the two arrowheads, but this is not the correct symbol, and which is the associated coil?
Graham Pearson
Member
Many thanks to all for the very valuable thoughts & advice which am now carefully considering over breakfast.
Thanks to NorthUp have now located the 448 fuses. Boat is a Colvic Watson Jura 35 motorsailer so had been looking for the fuse (as wiring diagram indicates) under the instrument "dashboard" in the wheelhouse. In fact the fuses are located between the control box & alternator on the electrical panel next to engine.
Voltage at batteries is 25.6, voltage at entry to control box is 15.7 and remains the same voltage at the + and - terminals for alternator (control box end), at the 448 fast fuse and at alternator itself.
Have (twice) had the alternator off and bench tested in professional auto shops. It is working fine and charging (35 amps); brushes are fine. Checked last Thursday
Re Bixter comments, have completely renewed wiring between alternator, 448 fuse and control box last Friday (new terminals and cables), however, will recheck the F connection.
With ignition on, when I push the two contacts together on the coil/relay, the warning lamp lights..so seems to me either this relay has failed in some way or it is not receiving current as presumably it should "click" open or closed.
As new regulator is only about 20 quid on Ebay will probably look at going that route and seeing what happens.
Thanks to NorthUp have now located the 448 fuses. Boat is a Colvic Watson Jura 35 motorsailer so had been looking for the fuse (as wiring diagram indicates) under the instrument "dashboard" in the wheelhouse. In fact the fuses are located between the control box & alternator on the electrical panel next to engine.
Voltage at batteries is 25.6, voltage at entry to control box is 15.7 and remains the same voltage at the + and - terminals for alternator (control box end), at the 448 fast fuse and at alternator itself.
Have (twice) had the alternator off and bench tested in professional auto shops. It is working fine and charging (35 amps); brushes are fine. Checked last Thursday
Re Bixter comments, have completely renewed wiring between alternator, 448 fuse and control box last Friday (new terminals and cables), however, will recheck the F connection.
With ignition on, when I push the two contacts together on the coil/relay, the warning lamp lights..so seems to me either this relay has failed in some way or it is not receiving current as presumably it should "click" open or closed.
As new regulator is only about 20 quid on Ebay will probably look at going that route and seeing what happens.
halcyon
Well-Known Member
The relay is surge protection only, no connection with warning light operation.
When you close it manually you are putting the A terminal to ground, providing a earth path for the lamp, check out continuity between regulator and A terminal on alternator. It could be a connection problem, or a fault in the regulator.
Brian
Graham Pearson
Member
Would like to thank all contributors to my problem when first posted back in May
Anyway, sourced replacement regulator on ebay (£22 from vehicleelectricsltd based in Birmingham) (was quoted 88 euros locally in France!)
Regulator installed and all now working, warning lamp going on and off when it should and batteries showing charge at 29.5 volts (24v system)
So, a big thanks to all for taking the time to respond.
Graham
PS, while it was not relevant to the problem, if someone could add to my knowledge.....would like to know how the earth works in my system (please see the previous photo that I posted sideways) it is the cylinder above the control box and it bears the legend " - IVE EARTH" (it does not say "LIVE") My question...what does the "IVE" stand for & what if anything is in the cylinder?
Anyway, sourced replacement regulator on ebay (£22 from vehicleelectricsltd based in Birmingham) (was quoted 88 euros locally in France!)
Regulator installed and all now working, warning lamp going on and off when it should and batteries showing charge at 29.5 volts (24v system)
So, a big thanks to all for taking the time to respond.
Graham
PS, while it was not relevant to the problem, if someone could add to my knowledge.....would like to know how the earth works in my system (please see the previous photo that I posted sideways) it is the cylinder above the control box and it bears the legend " - IVE EARTH" (it does not say "LIVE") My question...what does the "IVE" stand for & what if anything is in the cylinder?
halcyon
Well-Known Member
Negat .. ive and Posit .. ive, they just add - or + depending on polarity. could be a capacitor.
Brian
