Bedford MW charging issues.

[44GPW]

Ok, last year I had no charge in in my MW. Has new wiring loom and had alternator apart and checked brushes etc. During a long journey it kicked into life again and was then ok until I got it out again today. Wiring all checked and nothing loose. Need to know what else to check please. Thanks.

[Tony B]

Sounds like a good spray of WD40 and rev the engine up.

[andy1960]

Ok, last year I had no charge in in my MW. Has new wiring loom and had alternator apart and checked brushes etc. During a long journey it kicked into life again and was then ok until I got it out again today. Wiring all checked and nothing loose. Need to know what else to check please. Thanks.

 

 

 

Hi may be wrong here but I thought MW have dynamo rather than alternator so probably its lost its internal magnetism so will not "self generate". Start the engine and set to fast tick over. Remove cover from regulator box on the firewall and manually press the cut out solenoid briefly. This should "spark up" the dynamo and allow it to self generate the magnetic field it needs to produce power.

Hope this helps .

[Tony B]

Ah yes, brushes is a Dynamo :red: Try repolorasing http://www.dynamoregulatorconversions.com/polarising-a-dynamo.php

 

BUT very big BUT, disconnect regulator box, BEFORE you do so.

[Richard Farrant]

Ah yes, brushes is a Dynamo :red: Try repolorasing

 

 

If this MW does have a dynamo and control box (and not an alternator), the fact that it charges intermittently points more to the CAV control box. This type do suffer with age and even n.o.s; ones can give problems.

 

If the ammeter was showing a correct charge reading when it was working, then unlikely to be a polarising issue.

[44GPW]

Thanks for the feedback and suggestions chaps. It IS a Dynamo and Control box set up.....just my rubbish description!! I did some basic checks today using a tester and have charge coming out of the Dynamo but nothing getting too the battery so it does point to a fault in the control box as you suggested Richard. Are these repairable or is it a case of replacing?

[thedawnpatrol]

Richard,

 

Check the contacts where the fuse pushes in on the lower part of the control box, these often get dirty / corroded give it a rub with some emery cloth.

 

other than that the CAV boxes are quite often available, but very few are NOS. I have several on the shelf, in various states.

 

Cheers

 

Jules

[Richard Farrant]

Thanks for the feedback and suggestions chaps. It IS a Dynamo and Control box set up.....just my rubbish description!! I did some basic checks today using a tester and have charge coming out of the Dynamo but nothing getting too the battery so it does point to a fault in the control box as you suggested Richard. Are these repairable or is it a case of replacing?

 

Richard,

The electrician I use is not available for work now, but he found faults in these CAV control boxes. I have had a number rebuilt by him and if I recall he removed the old innards and replace with the workings of one of the common 60's period boxes, might be an RB108, would have to check at work. He always tested these with the dynamo on a test rig, to set them up.

If you do clean the contacts, wipe some paper through afterwards else you may have a bit of muck holding the points apart.

[44GPW]

Ok, i will check the fuse holder and points, thanks.

 

Incidently, i did notice that if i briefly push the contacts together manually i got a discharge on the gauge. Is that normal?

 

What size fuse should be in the control box as i current just have a piece of fuse wire.

 

Thanks

 

Richard

[44GPW]

Also, what's the exact model type of the box i'm looking for?