Bosch Dynamo & Solid State Regulator

[Mr Fixer]

I have a 1968 International tractor. I rewired it a while back,for basic functions. The battery hadn’t charged for years.

The dynamo was stripped, cleaned and bearings renewed. The brushes have plenty of life on them and the commutator looks in good condition. I polarised it before refitting.

I’m struggling to get this new regulator to work. The battery is now overcharging.

I bought a new DVR4N regulator, from Electrodynamic Solutions here in the UK. The old electromechanical regulator was worn out. As far as I can tell, I have it wired correctly, with good earths but I must be missing something as it still overcharges. Hoping someone may be able to help. Have hopefully attached original wiring diagram and pdf of new regulator information. Thanks.

 

[zzr1200]

What is the charging circuit voltage (across the battery), plus the charge ampage while running right after engine start up, and then does the charge ampage reduce after a while?

Have you tried checking/reading the battery voltage while the engine is cold cranking, but not running??

I presume the tractor is diesel powered...

 

[Mr Fixer]

The voltage across the battery is about 13.5 after startup, but as soon as you build the revs up a little bit, it goes to over 15v. Not sure on the amps. I was wary of letting it run too long at the higher voltage. I have fitted an ammeter to the system and it drops full scale when cranking, but doesn’t show any charging when running. Assuming I have it wired in correctly.

 

[Mr Fixer]

To add a little more info on this. I have wired like the original regulator. This is the second new regulator that has been fitted. The first one was assumed to be faulty and when it was sent back and tested, it was not functioning. I was told that a load dump had occurred and destroyed the clamp within the unit. I was told to add a varistor to help protect the new regulator, which I have done. Also put in a TVS diode

 

[Mr Fixer]

Here are some photos of the dynamo and old regulator, in case they are of any help. Bottom pic is one I got off the internet, but believe this to be how it would be wired originally.

 

[zzr1200]

Casing seem to point towards 14v 16a, I could see a modern day electronic might vary slightly, plus the condition of the battery fitted/used.

I'd be inclined to re-check all the connections in the charging circuit, this might be of some help....... wth the new regulator wiring.

 

[Mr Fixer]

I believe this is basically how I have it wired now. Please excuse my poor drawing.

 

[Mr Fixer]

Casing seem to point towards 14v 16a, I could see a modern day electronic might vary slightly, plus the condition of the battery fitted/used.

I'd be inclined to re-check all the connections in the charging circuit, this might be of some help....... wth the new regulator wiring.

Thanks for the replies. I’ll go over the connections again, but I’m not seeing anything obvious, to me anyway. Battery was new last year and is still in good order.

 

[waddycall]

What does the 15 on the DVR4 refer to?

 

[Mr Fixer]

What does the 15 on the DVR4 refer to?

Current limit, so 15 amp.