r8516874

Clive, I've got some more measurements for you. With the relay pushed in: G=0.1V M=0.1V Q=0V I high=18.1V I low= 0.52V X=25V Y=18V Z=24.8V J=24.8V K=24.9V I hope these can help you. My system is still working fine and the relay is clicking away. I've moved to another problem now. I took it out for a bit of green laning and it was a bit wet and my indicators have given up. More fault finding to be done. Also my heater fan is shorting out somewhere. Its already gone through 2, 35amp fuses. Its a good job I love the old girl. Jim

Clive, Sorry I've been away so long. Duty calls and all that. It looks like that resistor is a definate weak point. Your has well and truly gone. I've no idea about re winding it but a shorting wire definatly gives you a working system. I got some results for you but I've go to re-do them while pressing the relay closed. Ignition on, everthing connected: G=0.35V M=0.05V Q=0V X=0V Y=0V Z=0V J=0V I=0V and K=0V With the engine running and the system charging. G=0.4V M=0.2V Q=between 13V and 25V X=28V Y=20V Z=open line J=open line K=28V I=1V I definatly own you a beer or few for all the help you've given my. Thank you very much. I'll get back to you with the rest of the results, Jim

Clive, Problem solved. My dad and I took the resistor off and found that there was a break in the wire so we sorted the wire out and all is now good. I've got a steady 28volts getting to the batteries. All thats left now is to find the rest of the system to put it back as god intended. Thank you very much for all your help. You've helped me learn alot and I'm very greatful. How is your 'all charged up' part 4 coming on? I hope your having some plain sailing. Jim

clive, done it. I've got 28volts again. Your a star. I've put a bit of wire accross the resistor to short it out, the wire has about 0.3ohms of resistance. I take it will run like that. What can I do about fixing the problem? All my thanks, Jim

Sorry clive in my haste I miss read you. is the resistor connected only at one end, circled? Because if that is so I think my resistor must have failed.

Clive, Of cause you were right. There is no connection from point X to the board. Where is it ment to connect to and can i just solder a new bit of wire in from point x to either the board or the next resistor?

clive, your one hell of a man. I'll take the fiddle with the boards. I'm going to try and tackle it now i'll let you know what happens.

ps check for volts from U and V and neither had volts with the relay arm pressed.

Clive, I got no volts on any of the terminals you labled in the picture. The ignition was on and the relay arm was pressed and I checked with it not pressed. The generator was not connected, nor was the cable to the generator. Does this mean that the battery power in could on the wrong terminal no putting the volts where we need them?

I've just tried again and I got no volts on F at all and the same goes for V with and without the relay arm pressed in. i checked the earthing for the panel casing and it is good. I guess this gives us some clue as to what is going on. A new panel it maybe? Jim

Clive, I think we may have found some faults. With -ve pin on earth and +ve pin on F I read no volts. Then +ve pin on X and the relay arm pressed down it showed 24V. As the relay was released the voltage started slowly dropping. With +ve pin on V there were no volts shown. These readings would sugest that the generator panel is at fault wouldn't it? Is it possible to point the finger at a component and then replace it? Or shall I try and find another panel? I have attached a picture of where my earth wire is connected inside the panel to confirm it is in the right place. (indicated by the arrow).

I've got it on a bench but I can put it back in the vehicle. Where in the generator panel is the earth cannection? or the battery connection for that matter. I only have a really rough Idea where things were connected to. Could you do me a picture of the 'outputs' of the generator panel so I can make sure its wired up correctly. Lets hope we find something.

Clive, I got the results for the battery bulb test. +ve prod on W and -ve on the heatsinks and the bulb lights up. Reversed and it does not. -ve prod on X and -ve on the heatsinks and the bulb lights up. Reversed it does not. -ve prod on F +ve on the heatsinks and the buld lights up. Again reversed it does not. Not what I though was going to happen but that gives us proof that the diodes are doing something inside the generator. I'm still trying to get hold of an AVO to measure the resistance. On a light note how is your new project getting on, all charged up 4? Hope all is going well. Jim

That sounds rather painful! Are EMER's the military publications? If I know the military then everything is in the wrong place and repeated at least 4 times. Making sure its far to expensive. I'm sure putting heads together can make sense of the mess. But even so it sounds like your making good progress. I'm on the edge of my seat in anticipation, it should make great reading. I've been out working on other machines today and your right, playing with images in paint is much warmer. I have just got the feeling back in my right hand. The things we do for vehicles we love.

I'm afraid it is a digital multimeter. I will try using the battery method and see if that can help me. If all else fails I'll try and find a coil meter. Yes the plugs were all connected again and the control panel was wired up how ever it was wired. Where did you see the power diodes? Are they an easy fit? I have a feeling that these diodes could be the cause of my problem's, but I'll Soldier on.

Clive, It is definatly a mk 3. It says so on the black plate on the side of the case. I'll change the battery in the multimeter and do another set of readings. Aparently the battery has never changed, so says my father. I'll also get another multimeter from work. I'll give the bulb and battery method a go and see what I get. When you talk about the heatsinks where on the generator do you mean? The generator or panel didn't smoke burn or overheat. But I remember doing some welding in the footwell. I disconnected the generator, panel and batteries but could I have still caused some damage. Surly if that is the case the diodes would have broken down giving less resistance not more. Can the generator/panel be repaired if I find a faults with them? New diodes, reisitors, etc. Hope we get there eventually, Jim

Clive I have the full readings for you, and I hope you can make sense of them, because I can not. I have put the new readings first followed by the readings I took last time. They are both from the same generator. I'm sorry, the readings were in megaohms not milliohms as I said last time. Firstly with the negative lead on pin W. P= 22.3Megaohms/4Megaohms T= 22.3Megaohms/4Megaohms R= 22.3Megaohms/4Megaohms X= Open line/21.56Megaohms F= 28.5Megaohms/4.1Megaohms Then with the positive lead on W. P= 0.807Megaohms T= 0.807Megaohms R= 0.807Megaohms X= 1.884Megaohms F= 2.87Megaohms Then, the U and V results averaged with turning the generator over. U-V= 24ohms V-U= 26.8ohms I hope you can decifer something from these readings clive because it is all Greek to me. How could I tell what is at fault? Do the batteries provide the 24volts for the field windings? If they do I wonder if their not wired up correctly?

There is a good chance I am wrong, I shall double check the readings again tomorrow. I'm positive that I have a mk 3 panel, but I will try and get a picture to confirm it. It looks the same as the one on page 13 of all charged up part 3. Does 24 volts come from the generator pre-rectified then? Through pins u and v?

Sorry Clive, it was a small m so they read milli ohms. With the probes reversed the reading where higher, I can't remember exact figures. I'll check again if it will help. Are there any internal checks I can do on the generator panel? At what point would I find the 28 volts for charging? After the generator, or out of the panel?

Clive, Well I've got some very strange results. Firstly I think I've got a mk 3 generator. The generator that was on the landy when it stopped charging read O/L on all positions apart from U-V, 27ohms and W-X, 1.836ohms. So I guess we can saftly say that one's dead. But the spare on I had, with a dodgy bearing, read diffrently. W-P, 4.0m ohms then climbed to 4.7m ohms W-T, 4.0m ohms then climbed to 4.7m ohms W-R, 4.0m ohms then climbed to 4.7m ohms W-X, 21.56m ohms W-F, 4.1m ohms then climbed to 4.9m ohms U-V, 17ohms. All these readings really have confused me. The only part I understand is the cable from the gen to the panel is good. there is still no volts with the generator with the dodgy bearing in and the panel wired up how it was. I have a feeling the whole system may have given up, or at least there is more than one fault. Tomorrow night I'm going to try and work my way through the step by step fault finding guide, so I'll let you know how that goes. Jim P.S All charged up No.4 sounds good to me.

Thanks for the advice on the forum, I've joined up. Lets hope I find somthing. Unfortunatly the workshop wasn't any help at all, I dont think normal foke have dealings with systems like these. The resistance readings would help, I will have my fluke with me and I can borrow a megger from work. I've tried to add some pictures, so I hope they help. One I think is the shunt box and the other with the cover open just contains two relays. Of cause I've also got the generator, the generator panel and the cable to join the two.

I obviously have a couple of problems. not knowing where the fault/faults are and the system not being complete in the first place. I think completion of the system is my first goal, then i can run through these tests. Do you know anywhere i can buy the cable from the generator panel to the shunt box and from that to the ammeters and the vehicle batteries? I have been to the workshop and got the generators back. What tests are you suggesting? I think I have a wiring diagram in a manual I've got. Jim

Hells teeth! Thats one impressive looking vehicle. What is it? Is that all armoured? It must be interesting to drive. My landy is pretty much standard. Its lost the military HT leads which have been replaced with peugout ones, and as you know the charging system is canabalized, at best. I keep my eyes peeled on Ebay, but i'm not having much luck. I wrote to the royal logistic corps museum and got the B record card but I cant make out much of it. The Reg was 18 GN 53. It was in service from 01/1/1978 and left in 23/09/1993. 12 years before I joined up! Its been to, Ashchurch-ADPCON, 8 sig regt and S/O Aston Down. Thats all I can make out.

So you just check that there is continuity and therefore it should work. Is it the diodes that get damaged and stop the generator working? So where do the vehicle and radio batteries connect inside the generator panel. I've been looking at some pictures and I think the second/outgoing plug is missing and the vehicle batteries were just wired direct from the gen panel to the starter relay and earth. Where does the vehicle battery lead go after the shunt box?