Defender Td5 Alternator Overcharging

[JohanJvV]

According to my MadMan, My Alternator charges to 14.3 volt after a startup in the morning and then later subsides to 13.9 volts where it stays for pretty much the rest of the time. (Normal daytime driving no lights etc).

But the National Luna Dual battery monitor shows that my alternator is overcharging with the 4 top green lights flashing the entire time.

Should I worry and change the Voltage Regulator on the Alternator before we go on out Botswana trip?

[Landyluvver]

13.9V is certainly well within the safe limit for charging and a simple test with a multimeter will confirm whether the Madman or NL gauge is accurate.
i would for peace of mind just have someone confirm the condition of the battery before setting off on the trip. i know the batteries are new but one can never be too sure. if faulty, they can swop it out under warranty before hitting the road.
you have had so many issues with the alternator/s since getting the batteries replaced that one would never know if there could possibly be residual damage.

[JohanJvV]

Originally Posted by Landyluvver

13.9V is certainly well within the safe limit for charging and a simple test with a multimeter will confirm whether the Madman or NL gauge is accurate.

Tested on both Batteries with the Multi-meter while Landy is idling.
Multi-meter - 15.2V on both Batteries
MadMan was on 14.3V
NL was Flashing
Both batteries was 12.6V when Landy was switched off.

So what now
This is a genuine Land Rover Alternator that was reconditioned.

Do you get a Voltage Regulator Separately for a Land Rover Alternator

[Landyluvver]

voltage regulators are available seperate for any alternator.
it is not normally required for cars but is used extensively to protect sensitive electronics. many car chargers for laptops etc have this built in to protect against voltage spikes.
two points that need to be considered when shopping for one :
1) must be able to handle the amps - 120 Amp would probably be the minimum spec.
2) should preferably be adjustable so you can decide where to cap it. 14.4V is normally the safe cap. many come preset for 13.8V.

older cars used to be fitted with the electromechanical regulators.
sure something like this is still freely available but more modern electronic ones are more reliable and cheaper.

[hgbosch]

Hi guys

interesting debate. Just remember one thing, no matter how fancy the alternator or the voltage regulator, a battery in a motor vehicle cannot get fullly charged while driving it. Not even on a 5000km journey.

The 12.6V you measured is open circuit voltage and ideally this should be measured about 24hours after the vehicle got sitched off.

For peace of mind, proceed as per LL's suggestions and also fit a CTEK D250S secondary battery charger. This WILL BE ABLE TO FULLY CHARGE the secondary battery, as it is an inverter charger. The load on the alternator will show that this charger draws more current then a normal 2nd battery conditioning system, but your beers will remain cold

[Landyluvver]

15.2 is very high and you will run the risk of damaging the battery/ies.
fitting an aftermarket regulator may be a good idea.
simply cannot understand that the regulator in the alternator will allow such high voltage. a regulator when faulty normally drops to 0 rather than allow higher voltage.
2 devices show overvoltage which should be conclusive enough.

[JohanJvV]

Surely since this alternator was reconditioned a faulty voltage regulator should be replaced under some warrantee.

[Ride_Alot]

Keep us posted - I have a Discovery D2 TD5 ES with a nippon-denso alternator and the NL monitor always flashing until alternator is warmer and then goes to 14.2 / 13,9. I have spoke to NL and they said it is normal for newer Alternators to give more than the 14.4v. I was not happy so I phoned around and got the same reply from a few 4x4 workshops... One said - be glad your alternor is working great! I have 3 batt's fitted and would like to be sure I am not hurting them. So..if you find a nice voltage regulator that is not too expensive let us know.
tx

[Landyluvver]

shopped around a bit and body mounted voltage regulators are available from several spares shops. prices vary depending on make obviously.

http://contentinfo.autozone.com/znet...VR603/image/2/

this is an example of one.
it would obviously require some wiring but should not be difficult.
one thing that concerns me is that some of these alternators are wires for 2 wire and some for 3 wire. the 3rd wire must have some purpose.

[Ride_Alot]

I have found a lot of these type of things at sparxx.
Not sure if you have them there might be worth while..
http://www.sparxx.co.za/plunger-bosc...m-p-38216.html

[JohanJvV]

Originally Posted by Landyluvver

one thing that concerns me is that some of these alternators are wires for 2 wire and some for 3 wire. The 3rd wire must have some purpose.

When I had some trouble with the previous Alternator, the Auto Electrician said there must be 3 wires and they installed a third wire. The Landy always just had the two wires.

Could be something to do with this third wire. Don't know where its going.

[Landyluvver]

one wire normally supplies power to the field coils (without the alternator simply cannot excite the field coils and the alternator cannot generate current. the regulator is like a governor. it regulates the current to the field coils thereby limiting the amount of current the alternator can generate. as the voltage goes up, the regulator "clips" some of the voltage to the field coils and as the voltage drops it "opens up" to allow more voltage to the field coils. these units normally work with a Zener diode which either works or does not.
the second is normally the wire to the charge light on the dash.
no idea what the 3rd would do?

[JohanJvV]

Some Interesting Reading RE Alternators:

[JohanJvV]

It would the three wires are connected as follow:

B+ Main Bat Feed
D+ Warning Light
W Phase Terminal (12V)

Also read this on another forum

"There should be 3 wires coming out of the alternator.
One thick one going to the +ve of the starter (that's the main charge out to the battery)
Then 2 smaller ones, brown/yellow which feeds the red light (and is obvously working as the red light illuminates),
and a green/yellow which goes through a header joint and down to "passenger compartment fuse box" , it's fuse # 6, 10amp, the red light is fuse # 7, also 10amp"

And note the following RE LandRovers:

"Land Rover common faults
Most Land Rover Defender, Discovery and Range Rover 2.5 diesel models
regardless of year of manufacture all seem to suffer from the same problem
BAD EARTHS on both Alternators and Starter Motors.
Before installing the replacement unit on a vehicle with a discharged (flat) battery,
non-start or non-charging please check the condition of all earth connections within
the engine bay and if corroded replace.
Affected part numbers are QA1502, QA2097, QS1461, and QS1693.
Another Land Rover fault is quite an unusual one:
On the Defender and Discovery TD5 models the alternator is fused through the
brake / stop light circuit.
Should the fuse for the brake lights blow the alternator will not charge, always check
this fuse before replacing what appears to be a faulty alternator.
Affected part number is QA4120."

[JohanJvV]

Originally Posted by Ride_Alot

I have spoke to NL and they said it is normal for newer Alternators to give more than the 14.4v.

Interesting, have picked up the same story on another forum:

http://www.landyzone.co.uk/lz/f38/na...ler-94829.html

National Luna Dual Battery Monitor & Controller
It came to my attention that myself & a couple of other users have had issues in the cold weather with these units.
The meters are reading a constant overcharge state on both batteries from cold start either until the engine has been run for a while or until electrical components are in use...all alternators concerned are outputting the correct charge...here's the response from Luna support...

Greetings Mr Fossett

(Looks like you're having one serious winter over there)
We are typically seeing more of this "error" especially with modern vehicles. In most of the reported cases, the alternator output voltage is over the over-charge warning voltage of the monitor (set at 14.65V). Most manufacturers of lead-acid batteries specify a maximum charge voltage of 14.6V.
We are also seeing an increase of battery failures due to excessive overcharge.

This happens quite often in cold conditions as many alternators compensate for the low temperature and increase their output voltage.
Normally this only happens for 10 to 15 minutes or until the engine temperature has increased sufficiently.
Turning on heaters, lights or other accessories help to bring the voltage down to within range by loading the alternator.

It is normal for the monitor to react in this way simply because it is warning of the potentially dangerous charging voltage. Unfortunatelly you will not be able to eliminate this warning.

We are working on an intelligent means of dealing with this type of warning while still keeping the health of the battery of high priority.

Kind regards
Steven Lambert
Product Development Manager
National Luna

[JohanJvV]

Originally Posted by hgbosch

Hi guys

The 12.6V you measured is open circuit voltage and ideally this should be measured about 24hours after the vehicle got sitched off.

12,4 V on both Batteries.
Vehicle was not used today

[DaveB]

My TD5 reflects the same on my Madman and National Luna monitor.....But only until the solenoid engages, and early winter mornings when its around 0 to 5 degrees. I had my alternator checked and it was fine.

I just switch off my NL alarm in winter during normal driving......

[JohanJvV]

Originally Posted by DaveB

My TD5 reflects the same on my Madman and National Luna monitor.....But only until the solenoid engages, and early winter mornings when its around 0 to 5 degrees. I had my alternator checked and it was fine.

I just switch off my NL alarm in winter during normal driving......

Dave, I think you are correct.

I have seen today after picking up my Explorer that when the NL system kicked in and thus the alternator charging three batteries (Crank, Dual & Explorer) the voltage dropped on the Madman to 13,7V and even on the Mechanical voltage meter to 13,5V. The NL system just kept on flashing.
Starting to think there is a problem with NL system.
OK I could test with a Multimeter at that moment.

Maybe I should install a body mounted Voltage regulator to use when just driving around and Dual Battery is disconected and no towing, with an overide switch for when towing and Dual baterry is connected.

[JohanJvV]

Can somebody please help me URGENTLY, we are leaving Saturday to Botswana and I am still having trouble with this.

Had the Alternator out today and they tested the Voltage on the Bench. It was charging at 14,7V.

As soon as we fit it back to the car the Voltage on the battery is 15,1 V.

I am really to worried to leave like this.

Who is an expert on Landrover Alternators and wiring from the Alternator.

The whole story about 2 and 3 wires from the Alternator is concerning me.

[OSIYEZA]

Johan,
I have the same problem with mine....damn alarm makes we crazy...I have pulled the damn thing out....It seems that we all have this problem.It has to do with the cold weather....have not had a problem with the system in summer.

Had both batteries on my cteks the weekend (also leave on holiday Friday) and now the alarms on BOTH "arms" of NL system is going crazy in the mornings...

Fredor

[Nielbd]

AFAIK, the 3 wires is:
1. Thick wire = Main current output to battery
2. One of thin wires = Charging indicator lamp
3. Also a thin wire = Voltage sensing wire. This wire is used to sens the exact
voltage at the battery. In the two wire setup the voltage gets regulated with reference to the output voltage on the alternator. At low current demands this is no problem. Eg. Resistance of wire from alternator to battery = say 0.1 Ohm.

Volt drop over cable at 1 Amp current drawn.
V=IR
V=1*0.1
V=0.1V Volt drop to battery

But

Volt drop if 20 Amps is drawn
V=IR
V=20*0.1
V=2V Drop to battery

So the 3rd wire is used to sens the actual voltage at the battery as the volt drop in the 3rd cable will be very small(almost no current flowing).

Hope this helps.

[JohanJvV]

There are three thin wires coming out of the plug, as well as the main thick wire for the main current.

Taking it to another Auto Electrician today. Must get this sorted today.

[JohanJvV]

Originally Posted by OSIYEZA

Johan,
I have the same problem with mine....damn alarm makes we crazy...I have pulled the damn thing out....It seems that we all have this problem.It has to do with the cold weather....have not had a problem with the system in summer.

Had both batteries on my cteks the weekend (also leave on holiday Friday) and now the alarms on BOTH "arms" of NL system is going crazy in the mornings...

Fredor

What is the actual voltage measured on your battery with multimeter?

[JOHLIEN110]

Johan, know the feeling.
Phone george 0837581519
be +

[JohanJvV]

Fixed

There must only be two wires in the plug, not three.
New Voltage regulator (Genuine LR) with 2 wires and its working fine.

[Tsekela002]

Hi Johan,

I have the exact situation with my Dual-volt NL system. Mostly happen during Winter, where the 4 LEDs flash and the alarm bleeps it's heart out. I have checked my alternator out and it's fine. I phoned NL in 2009 when it first started, and they said that the unit is set just below my max alternator charge and may show over-charging in Winter when the TD5 computor compensates the alternator charge for cold conditions. They said it was normal and that it should not damage the batteries.

Been running like this for 3 winters now, just turn the NL alarm off as it irritates me. No issues and my 2 x Deltec batteries are perfect (1 x Lead Acid Deep Cycle and 1x Silver Chloride Deep Cycle).

No worries mate. You'll be fine.

Cheers

[Landyluvver]

JVV is up there somewhere in Bots with a blown 100A fuse.
as far as i can determine it drives the glowplugs.
Peter is trying to get him fuses from Gabs up to where he is but essentially he is stranded till the fuses arrive.
i presume one or so glow plug wires came loose and shorted out on the engine but only guessing.
this shows how important it is to go prepared.
you can never have too many fuses in the toolbox especially those little square block ones.
personally i believe the design is stoooopid!
the connectors push on like HT leads while most other diesels have a little lug that is bolted to the glowplug.

[PGJ]

If he can identify the problem and why the fuse shorted out , could he either not
swop for another fuse , or maybe just bridge the fuse out .

[tgwinduna]

Originally Posted by Landyluvver

JVV is up there somewhere in Bots with a blown 100A fuse.
as far as i can determine it drives the glowplugs.
Peter is trying to get him fuses from Gabs up to where he is but essentially he is stranded till the fuses arrive.
i presume one or so glow plug wires came loose and shorted out on the engine but only guessing.
this shows how important it is to go prepared.
you can never have too many fuses in the toolbox especially those little square block ones.
personally i believe the design is stoooopid!
the connectors push on like HT leads while most other diesels have a little lug that is bolted to the glowplug.

Hi LL
Just got off the phone to JVV problems seems to be solved When the fuse was changed in Thabazimbe they put in a 7.5amp fuse thinking it was a 75amp fuse. He has managed to get hold of in line fuse holders that take a large 35amp fuse so he is going two wire up 2 in parallel. He is carrying a spare 80 black fuse as a spare. So right now he is sorted.

[Landyluvver]

great news.
a landy always gets home somehow!
boer maak 'n plan. (even if it is a boere soutie!)
attached the photos of those stupid plugs that clip onto the glowplugs.
photo 2 is the tip of the glowplug where the plug clips onto.

[PGJ]

Just use the spare 80A fuse ? Or did i miss something ?

Good to hear he's winning .

[tgwinduna]

[QUOTE=PGJ;816298]Just use the spare 80A fuse ? Or did i miss something ?

Good to hear he's winning .[/QUOTE

That's what I told him to do. He wants to keep it as a security blanket!!!

[JohanJvV]

@ LandyLuvver & tgwinduna

Thanks for the advice and help while we were in Botswana, a Land Rover owner can alwys rely on both of you.

I disconected two of the Glo-Plugs (Still driving like that) and used the spare 80 amp fuse. No problems again.

Will sort it out when I have time, will probably replace the harnass.

[Landyluvver]

for the price of a harness i can do a lot of faultfinding!
i would possibly replace the glowplug wires as a start.
no rocket science.
need to check if any of those wires are down to earth.

[JohanJvV]

Originally Posted by Landyluvver

for the price of a harness i can do a lot of faultfinding!
i would possibly replace the glowplug wires as a start.
no rocket science.
need to check if any of those wires are down to earth.

Still feel the itch to replace it, especially if a new harnas from Dover is only R 4600, the Landy is 12 years old.