Technical Barry's Generator

[Fayray]

As some of you will have seen from my big adventure in Barry, my generator packed in just 40kms from home the other night. So now I'm trying to get to the bottom of the issue.

I have just run the voltage test outlined in the Haynes manual and I'm getting zero output. So it looks like the generator will have to come out.
However, I'm also wondering if there may be another problem in the charging system that caused the generator to fail. I only became aware of a problem because I fitted one of those volt meter/usb ports before leaving on the trip. When driving that last section with the lights on I noticed the volts had dropped to 11.7 initially not moving or bouncing around before steadily dropping until around 6v when the generator light came on and the engine started to stutter. Up until that point the generator light was acting normally (glowing a bit at tick-over and going out at around 1000rpm) even though it was clear I was running only on battery power. Should the warning light not have come on earlier?

I'm hoping it's just the generator so the next question is what is the easiest way to remove it? It seems like it's a difficult job with the engine in place?

 

[the hobbler]

I am told that it CAN be done with the engine in-situ, but you need another couple of arm joints--on each arm! Much easier to do the job with the engine out.

 

[JumpJet]

As someone attempting a fan swap with the engine in-situ, I’d highly recommend just pulling it out for the job. I don’t have ready garage access - the only reason I’m trying to do it with the engine in.

 

[Fayray]

Well I know I can take the engine out so that's what I'll do

 

[Fayray]

So I'm guessing I've found the problem:idea: Yes, those are indeed the old brushes

 

[fiat500]

So I'm guessing I've found the problem:idea: Yes, those are indeed the old brushes

That looks a mess! I would be cautious though; there's a possibly an issue with the regulator as a result of or resulting in that.

 

[Fayray]

That looks a mess! I would be cautious though; there's a possibly an issue with the regulator as a result of or resulting in that.

I was thinking that but would I not have seen some big voltage on my volt meter when driving? On reflection, based on some reading here, I was rarely getting a reading much above 13v and usually in the 12s. And with lights and wipers on struggling to make 12v which suggests the system wasn't working well even for a dynamo. When it failed the volt meter was unusually steady but dropping gradually, clearly indicating I was running on battery only by that point

 

[fiat500]

I was thinking that but would I not have seen some big voltage on my volt meter when driving? On reflection, based on some reading here, I was rarely getting a reading much above 13v and usually in the 12s. And with lights and wipers on struggling to make 12v which suggests the system wasn't working well even for a dynamo. When it failed the volt meter was unusually steady but dropping gradually, clearly indicating I was running on battery only by that point

I see your point, but those brush wires look burnt. I'd recommend that you fit an electronic regulator in any case. they aren't ridiculous in price and given that you use your car (what I would call) properly , it would be one less area ever to be likely to go wrong.

 

[Fayray]

I see your point, but those brush wires look burnt. I'd recommend that you fit an electronic regulator in any case. they aren't ridiculous in price and given that you use your car (what I would call) properly , it would be one less area ever to be likely to go wrong.

good idea. I will look into that

 

[Fayray]

update: New brushes and front bearing (fitted with dynamo in situ) has sadly made no difference to the voltage output. So I guess it'll have to properly come out now and have a birthday. I have sourced a solid state VR locally so I'll fit that as well

 

[Fayray]

Another update: I removed the VR and discovered the centre set of contacts, the ones that energise the field coil, had partially fused together. I fitted the new VR and the dynamo now works. I haven't taken him for a decent drive as he's now not idling so I need to look into that. When driving the last leg of our trip, over the very steep Rimutuka ranges, he started backfiring under deceleration and then wouldn't idle when I stopped. I'm wondering if the curse of the failing 123 dist is visiting me also:bang:

 

[lazylobster]

Good news on the VR fix, I fitted an electronic one when I first got madam. In the original service manual I have for the 500, it's quite a procedure to setup the mechanical VR. And I had an over charge issue killing the battery. Easy option in my book.


Do you have the original dist setup? Fit it back in, see if it cures ?

R

 

[Fayray]

yes, it seems a simple enough fix and not prohibitively expensive. I'll keep the old one as I'm sure it can be recommissioned.
I've had a look inside the the 123 and nothing looks out of place or suspicious. I ran the car again after cleaning the plugs that were a bit black for my liking but not too bad. It started and ran on choke as per usual and idled ok when warm and choke off. Then when I gave it a rev there were a few minor pops but it wouldn't then idle or start without choke. So I'm thinking maybe a carb blockage maybe.