Voltage Regulator

[ChrisB]

My IIA does not appear to have a voltage regulator, at least not in the location depicted here (which is unfortunately not my Series):



I only have the Lucas fuse box. I have scoured the engine compartment, but don't see it. Am I missing something? Do I need it?

Thanks for indulging another rookie question.

Chris

[Jeff Aronson]

Chris, if you're running with an alternator, then you won't have a separate one on the firewall. It's inside the alternator.

If you still have a generator and someone has mounted it elsewhere, just follow the wiring from the generator. You'll find it quickly enough.

Nice, clean wiring work by someone!

Jeff

[ChrisB]

Chris, if you're running with an alternator, then you won't have a separate one on the firewall. It's inside the alternator.

If you still have a generator and someone has mounted it elsewhere, just follow the wiring from the generator. You'll find it quickly enough.

Nice, clean wiring work by someone!

Jeff

Thanks Jeff on the voltage regulator question.

Wiring work photo was found at www.roverhaul.com.

[onecross]

hey yall, How do you tell if the alternator has a regulator? I installed a military rebuild motor like the ones rovers north sells and i also bought a new wiring harness for the hole truck and it doesn't seam to have connection to go to the regulator. any help would be gratefully appreciated.

-OneCross

[Jeff Aronson]

An alternator has the regulator built into its housing. It's a rare alternator that has an external regulator. Instead of magnetic tangs inside a box the regulator within an alternator uses diodes to perform similar functions.That's why, when the car is running, if the alternator is putting out too much voltage (>14.5 v) or too little (<13 v) you need to have the alternator either rebuilt or replaced.

Your harness may be for a Rover with an alternator, so there would not be a connection to an external voltage regulator. There would be a wire that goes from the ignition switch to the alternator - alternators need current to "excite" them into functioning.

Here's a link to a site that explains alternators in detail.

This site explains the differences between an alternator and a generator.

Enjoy!

Jeff

[onecross]

Thanks for the help Jeff I am hope to start my Land Rover up for the first time in two and a half years

-Mat

[S11A]

Hi,

I am not an expert at auto electrics, but just to make sure I am on the same page here is my understanding:

The voltage regulator as found in alternators (or externally on some alternators) is meant to regulate the voltage at around 12.5 - 14V.

The old Land-Rovers (and probaly a lot of other older British cars) had a separate voltage stabilizer that was meant to supply the instruments with around 10 or 10.5 volts (it may even be something like 8.5V, I am not sure). If I remember correctly (IIRC) this was needed for the gauges to function correctly. I am not sure if they will function accurately without this, or if they will. I know some people have put in new modern electrical systems with fuse/flasher/relay blocks fom companies like Painless, so maybe they can shed some light on this?

I would hazard a guess that this was needed for cars equipped with a generator (magneto) and primitive electrics (see 1 - 2 fuses for an entoire vehicle) and widely varying electrical loads to ensure that the instruments had a stable voltage going to them.

If that was all the stabilizer was for, you could probably do w/o it.

If it was also to deliver a specific voltage (10.5V), then you may still need it even if the voltage regulator in the alternator is putting out a steady 12.5V.

Here is a link to the voltage stabilizer at our hosts:

http://www.roversnorth.com/store/p-3003-voltage-stab-iia.aspx

I will look for a pic...

[S11A]

Here is a link that may explain the stabilizer better than I did:

http://www.freewebs.com/classicstabilizers/information.htm

[superstator]

Short version: modern senders can take in almost any voltage and reliably give a specific voltage back out to allow gauges to depend on that voltage level corresponding to a certain measurement. Old timey senders like those in most Series trucks could only apply a simple resistance to whatever voltage you gave them. To get a reliable measurement back at the guage, a an electromechanical stabilizer was used to provide a constant voltage source to all the senders. Your gauges will work without one, but they will read abnormally high most of the time.

I just put in a painless harness, and I used the stabilizer from that site - works like a charm. Before you assume you don't have one, though, you might measure the voltage at your fuel sender. It might just be squirreled away in your dash or inline someplace strange. Or you can ingore it and just learn to never let your fuel guage dip below a half tank or so (which is what I did before rewiring).


edit: doh