A good article is this one https://www.tccoa.com/threads/electr...pgrade.139242/ which details removing a 135 Amp old style alternator and adding a 200 Amp PWM type to an older Ford Crown Victoria. Our LR3/D3/RRS vehicles use the ECU to turn off the instrument cluster charge lamp, but other than that the article is very accurate in terms of how the PWM alternators operate and are controlled. These PWM types control wiring is critical to successful operation, so the first step in troubleshooting would be to verify that all interactions between the ECU and the alternator are functional, otherwise it would appear that the alternator would be in default mode and capable of charging, but only at a marginal rate.

EDIT: A very detailed YouTube analysis of a Ford F150 using the same connections as our machines (com, mon, sense, output) is at

 

I'm facing this exact same issue - glad to hear it's not just me, but I'm sorry this misery is so widespread.

Does anyone have a procedure for locating and checking all of the electrical system's grounding points? I want to try to eliminate everything I can before enduring the fun of removing and installing an alternator in an LR3 for the third time. Thanks!

 

Just Google (or other search engine) "find grounding faults in vehicles" and you'll see many methods, basically use a test lamp or multimeter, but sometimes these ground faults are very difficult to nail down, especially intermittent ones. Hope this helps you a bit, 3 alternators... ouch!

 

Not sure what voltages you are expecting to see. Like Abran said load up the electrical and if the battery is less than 12.0 volts, you need a new alternator. as for the right voltage, it depends upon state of charge of the battery AND the out side temp.

From the service manual section 414-02A Generator and Regulator:

The 'smart' regulator controls the output voltage from the generator to protect the battery; at low temperatures battery charge acceptance is very poor so the voltage needs to be high to maximise any re-chargeability, but at high temperatures the charge voltage must be restricted to prevent excessive gassing with consequent water loss. The EMS, which controls the regulator, will calculate the voltage set point required for the ensuing conditions. The 'traditional' regulator controls voltage against generator temperature, which means the battery temperature will lag a long way behind so there will be significant periods of operation when battery charging is compromised. information received from it's various sensors, hence voltage will follow the battery's needs a lot more accurately. With this system, the EMS can set the voltage by inferring the battery temperature from information received from it's various sensors, hence voltage will follow the battery's needs a lot more accurately.

Or something like that

Seems a changing voltage is normal operation for these things and of course good grounding is an absolute MUST.

Jeff

 

Hi Rufflyer...
the system works exactly as you state above, in my previous post (#31) of "Ford 'Smart Charge System' Alternator Not Charging" at time 3:55 he shows you a diagram of the charging system which is exactly the same as our LR3 charging systems except in the Ford F150 the Powertrain Control Module (PCM) is equivalent to the LR3 Engine Control Unit (ECU) as far as charging systems go anyway. The drawings, functionality and scope traces are also exactly the same, so you may ask yourself, "How can this be so?" Well, remember who owned Land Rover from 2000 to 2008? You win a prize if you guessed Ford, so it's no wonder that until Tata re-engineered many of Ford's ideas, many things to do with Land Rover were also part of Ford. I'd recommend to the OP a look at that 40 minute YouTube video for the story on how the LR3 (and part of the LR4) charge systems work in detail...

 

Yes, over the years I have seen more than few parts marked with FoMoCo on my 2006 and newer Land Rovers