Author Topic: 28v question  (Read 4923 times)

Offline Rangy35

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28v question
« on: May 18, 2015, 11:15:02 PM »
I have a 28v system that just stoped charging. The little info I have and what I have red on here it seems there is a few basic things to check first, this is what I have done so far.....
I did confirm there is no charging happening on the 28v system.
I did check all external connections, the cannon connector was secure, all battery terminals are good and clean, all batterys are in good health and I fully charged them with no sucsess for the 28v system to kick in, checked the power distribution box fuses all good.
Now from the limmited info I have puzzeled that there is voltage sensing wire and relay/switch that the 28v system needs to "see" to start working, this is the part I can not find in the info I have so I can test the circuit to make sure it is not something simple to fix the system, before I start looking into rectifires and such.
Just out of curiosity can the rectifire be bought on its own?

Thanx Johnny

Offline Philthy

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Re: 28v question
« Reply #1 on: May 19, 2015, 08:58:12 AM »
Johnny sorry I can’t help you but I’m keen to learn from you.

Would you be kind enough to explain how you isolated the fault (when you do) and undertook the repairs (I’m sure you’ll work it out and get it fixed) for the rest of us that may find ourselves in the same boat sooner or later?

Cheers Phil

To many times you read through posts on forums that have no closure.

Offline Carzee

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Re: 28v question
« Reply #2 on: May 19, 2015, 09:22:05 PM »
This sort of problem camp up before didn't it?
Sixty said
"If the batts are flat the generator will not have a 'sense' voltage and they do not self-excite  ;-)

Jump start the 24V batts and re-check output."

http://remlr.com/forum/index.php?topic=2958.0

Is it relevant in this case?

Offline isuzutoo-eh

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Re: 28v question
« Reply #3 on: May 20, 2015, 09:28:36 AM »
I had two brand new batteries that I charged and fitted then used as I drove around Tasmania for my fridge. Somewhere along the way the charging stopped and drew my batteries way down. Yet weeks earlier, the original/old batteries quietly boiled away with shorted cells.
The 28/24 volt system doesn't sound so reliable since others are having problems too.
-Mark
ex-NSW Police 2a. Civvy One Ten. 204-986 PT1-1.2. 50-543 project stretch limo. Formerly 48-803 110 FFR

Offline Philthy

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Re: 28v question
« Reply #4 on: May 20, 2015, 12:59:11 PM »
 Just a thought-


Are your new batteries flooded lead as the system was designed for?

Some of the new technologically advanced batteries need a particular type of power generation as this will kill them if they don't get what they need rather quickly.


« Last Edit: May 20, 2015, 01:01:17 PM by Philthy »

Offline Dervish

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Re: 28v question
« Reply #5 on: May 20, 2015, 02:57:52 PM »
I would love to help out, but the only schematic I know of for the FFR 24V system is incomplete - why not show how the DB is wired?


Offline Rangy35

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Re: 28v question
« Reply #6 on: May 20, 2015, 07:55:09 PM »
Johnny sorry I can’t help you but I’m keen to learn from you.

Would you be kind enough to explain how you isolated the fault (when you do) and undertook the repairs (I’m sure you’ll work it out and get it fixed) for the rest of us that may find ourselves in the same boat sooner or later?

Cheers Phil

To many times you read through posts on forums that have no closure.
Thanx Phill, and yes I will post what I found, my biggest challange is to convince the owner of the vehicle to leave it with me for a undetermened time, I will need to do the diagnostic the hard way and make plenty notes.

Offline Rangy35

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Re: 28v question
« Reply #7 on: May 20, 2015, 08:00:25 PM »
I would love to help out, but the only schematic I know of for the FFR 24V system is incomplete - why not show how the DB is wired?


I have the same schematic and I have the schematic of the 28v alternator, but like you said not the complete wiring diagram of the 28v system and how it incorporates the 12v system to make it work.
Thanx for the effort. 

Offline Rangy35

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Re: 28v question
« Reply #8 on: May 20, 2015, 10:39:12 PM »
Just another stupid question.....or two....
Is there a 28v ignition warning light on the 110?
Does the series Land Rovers with 28v system have a ignition warning light?

or three......

What is the chance that the Series and Defender are using the same 28v system? if so does anybody have a full and detailed wiring digram of the Series 28v system?

Thanx Johnny

Offline Philthy

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Re: 28v question
« Reply #9 on: May 21, 2015, 08:00:21 AM »
Just another stupid question.....or two....
Is there a 28v ignition warning light on the 110?  No just the meter
Does the series Land Rovers with 28v system have a ignition warning light? Same as your GS.

or three......

What is the chance that the Series and Defender are using the same 28v system? if so does anybody have a full and detailed wiring digram of the Series 28v system? DB is same. CAV is the same.

Thanx Johnny

Offline Philthy

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Re: 28v question
« Reply #10 on: May 21, 2015, 08:02:36 AM »
I would love to help out, but the only schematic I know of for the FFR 24V system is incomplete - why not show how the DB is wired?



 Is this the best we can get at the moment?

Series 3 Land rover parts list    RPS02090 ISS 2 NOV 1982

http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB0QFjAA&url=http%3A%2F%2Fwww.remlr.com%2Fdocuments%2FRPS%2F02090%2520-%2520Series%25203%2520FFR%2FRPS02090%2520ISS%25202%2520NOV%25201982.pdf&ei=T_1cVd2sPIbOmwWb84CQDQ&usg=AFQjCNF7GamhCY0pnnUZ3RQ6nVGrqnQ9Rg&bvm=bv.93756505,d.dGY

Page 471

Offline Dervish

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Re: 28v question
« Reply #11 on: May 21, 2015, 11:22:18 AM »
Ok, this is a best guess. The "sense" wire is switched by the ignition feed in the DB via 24V relay (35 in the document above) as it actually acts as a field/sense wire. Check for IGN at the relay switch input and then 24V at the relay output (which if I'm right should be a yellow wire).

Offline Rangy35

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Re: 28v question
« Reply #12 on: May 21, 2015, 07:59:40 PM »
Yup, I got the same conclusion today, you are correct it is the yellow wire and now I know at least what to look for.
Thanx everyone so far, it may be a while before I update, I am in the hands of the  availability of the vehicle.

Offline Rangy35

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Re: 28v question
« Reply #13 on: June 16, 2015, 10:21:42 PM »
Update......
Got the vehicle and checked this sensing wire out, it is the yellow wire and it is triggered by the ignition switch, nothing from the 12v alternator. The relay is in the distribution box in the back, it is the one on the left when the top cover is removed from the distribution box.
Unfortunately this 28V alternator regulator/rectifire is blown, now that I had a play with this system a bit.....it is baced on a motorcycle charging system, just all in one.
Can anybody tell me if the regulator/rectifire unit is available? and from whom?
I actually am trying to convince the guy to upgrade to a modern propper 24V alternator.