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Posted (edited)

hello all,

Got the Mw back on the road after a little bit of work,

TruckPictures006.jpg

 

Braved the rain today to take it out for a run. All was going well till i notice the ignition light starting to glow. It still ran ok and started a couple more times,so i guess the dynamo is charging but the cut out is at fault. I went to see an old chap who used to drive them in berlin in the 50s and he said to clean the points, in the cut out with some fine emery. By the time i'd got home the battery was dead and it wouldn't start, so i've put the battery on charge and left it till the morning, any suggestions, or adivice?

 

.

Edited by rippo
Posted

It could be many things. Worn/stuck brushes in the dynamo, contamination on the brushes, a loose/broken wire, or indeed as you suggest dirty contact in the regulator.

 

I'd probably start looking for loose/broken wires.

 

Next with testing the dynamo on the vehicle, and go from there. Disconnect the wires from it and connect its two contacts, connect a 50v DC voltmeter between the wire and a good earth, and start the engine. The reading should rise with the revs, assuming a 12V system it should start at 8-9V at tickover, and climb to 30V ish at higher revs. No output suggests the fault is in the dynamo.

 

With voltage regulators it is often dirty contacts, although I've had melted soldered joints, broken wires, and totally burnt out ones in the past.

 

The above is based on the older Landrovers, but I hope would apply to any dynamo based charging system.

 

Jules

Posted

I had an identical problem with my WOT2 when I went to Normandy in 1984. After a lot of checking, it turned out to be a broken wire in the Dynamo.

Posted

I've tried acouple of things this morning. Cleaned the points in the cut out, and checked the wiring, It has had a new loom on it so i don't think it'll be a broken wire. The light is only really dim some times not at all. So i think its more dirty contact somewhere rather than a broken wire.

Posted

Ok i've tested he dynamo and it's doing as it should, i've swapped the battery just in case and thats made no differance. So i guess the problems in the cut out, how can i test it?

 

Also i noticed the ampmeter isn't showing anything, any more suggestions before i strat looking for a cutout?

Posted

Have you got the regulator set up properly? The instructions should be in teh nmanual. clean everything up and double check you have the wiring on the regulator. The other thing,Did you POLARISE the dynamo?,

Posted

Polarise the dynamo? whats that?

 

I'll have a look in the manual how to set up the regulator, all the wiring is correct as i haven't touched it.

 

I've been out in it again today, from stoke to manchester, and then back again had to use the lights on the way back and it still turned over when i got back. So it seems it dosen't run the battery down when its running, but i guess it isn't charging it up either.

 

i leave for normandy on friday so need to get it sused by then.

Posted
Polarise the dynamo? whats that?

 

So it seems it dosen't run the battery down when its running, but i guess it isn't charging it up either.

 

 

 

Dynamo sometimes needs repolarising, Lucas used to supply replacements polarised for +Pos earth systems, if the vehicle was -Neg earth then it needed repolarising. This is the procedure;

 

With wiring disconnected from the dynamo, connect a length of cable to the insulated battery terminal (live) and flick the other end several times to the "F" terminal of the dynamo. Remove cable and reconnect wiring to dynamo.

 

A test to see if you are getting any charge to the battery, with engine stopped, check batery voltage with a meter, then start up and measure again with engine running fast, a higher voltage indicates a charge. It may not be enough to put out the warning light though.

Posted

The warning light is out when it's on tickover and only becomes slightly brighter, i can only just see it, when the engine is reved, and there's no reading at all on the ampmeter on the dash.

 

I've read up on the adjustment of the cut out but it takes more tools than i have, but the way i've read the manual i would need to adjust a new one, so either way i'm stuck.

 

Is it worth me sorcing a new cut out and trying that? I really need to get it fixed.

 

I think the dynamo's working fine, just the charge isn't getting through to the battery.

Posted

Hello,

Right I've tried repolarising the dynamo, i followed richards instructions above but i didn't get a spark from the f terminal, as i was expecting i spoke to john mortor earlier and he said to flick it on the casing so i did that and got a spark, but its made no differance its still not charging. I've checked the voltage at the battery and there's no change when its running. So i guess it must be a fault with the regulator.

 

Luckily rag trigg might have one, and he's only up the road. When i spoke to john mortor earlier he also has boxed originals, but he said he's had trouble with ones he's used straight from the box, due to the age, but he has a modern alternative cased in the original box. So i'm not sure what to do, Stick with the original, or go for the modern replacement.

Posted

Hi

 

I've a few of those regulators here for the Morris'( they seem to be a common fitting ). I've never attempted to adjust one but I've got some data and stuff on them..A friend in the UK posted me a NOS one in the box ..it looks pretty but dont know how it will behave .

 

Yes sounds like your regulator isn't adjusted to 13.8 Volts ..the red light indicates the current flow is happening in REVERSE ..that is it is flowing from the battery instead of into the battery ... The CUT OUT , which is mounted inside the same box, does another job, it doesn't regulate the voltage at all .. it's a simple ON or Off relay that disconnects the generator field coils from the battery when you switch off the motor. The Cut out isnt faulty, its the regulator part that is

 

Mike

Posted

Depending where you are: There is a great place at Welling south east London called Charge and Start. they seem able to work near miracles rebuilding stuff. Tel: 020 8301 3144

Posted

Thank you goanna, thats the reply i was looking for, it confirmed what i thought.

 

I ordered a new style replacement from john mortor, he said he'd had a number used straight from the bees wax packaging that were faulty, so i think it's a bit hit and miss, and he did say he'd been told they were like that when new in the 50s. Even thoe its brand new from a box its still at least 50 years old.

 

Hopefully it'll arrive tomorrow and i can fit it tomorrow evening and i'll be all ready to go.

 

Thnaks tony but i'm in manchester, hopefully with this new style one and with the jolley box, i should never break down again!!!!!

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