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+--- Thread: charging question. (/showthread.php?tid=2580)
RE: charging question. - Ray White - 31-03-2019
You are quite right Bob. Sorry, my mistake. The contacts still open when the when the ignition is switched off so there is no risk of anything happening.
I should think about what I am writing before posting.
RE: charging question. - David Stepney - 01-04-2019
Although I will admit that electrics are not my strong point, from your symptoms, it appears that there is a small permanent current running through your cutout's voltage coil. It is not enough to fully energise the solenoid to pull the contacts together, but just sufficient to hold them together once closed.
If it goes when you turn the ignition off, the only place such a small current could come from is via the ignition warning lamp. This would suggest a short between the current coil and the voltage coil in the cutout. That is where I would look anyway.
Hope this helps.
RE: charging question. - Ray White - 01-04-2019
(01-04-2019, 12:18 AM)David Stepney Wrote: Although I will admit that electrics are not my strong point, from your symptoms, it appears that there is a small permanent current running through your cutout's voltage coil. It is not enough to fully energise the solenoid to pull the contacts together, but just sufficient to hold them together once closed.
If it goes when you turn the ignition off, the only place such a small current could come from is via the ignition warning lamp. This would suggest a short between the current coil and the voltage coil in the cutout. That is where I would look anyway.
Hope this helps.
Thanks for your thoughts David. The two coils both occupy the one bobbin which makes such a short difficult to isolate. I have my suspicion that the correct polymer (formerly Shellac) insulation may not have been used when the cut out was restored as what may only be paint has rubbed off in one or two places. I will get the auto sparks chap to take a look tomorrow.
RE: charging question. - David Stepney - 01-04-2019
I think that the way to check would be to disconnect the 'E' terminal wire from the cutout (the voltage coil is wired between the 'D' terminal internally and the 'E' terminal). Turn on the ignition and check between the 'E' terminal and the earth wire you have just disconnected and see if you have a voltage. You should have none at all. If you have a voltage, and it may be quite small, as there is a 30 ohm resistor in the warning lamp, then you have a short.
RE: charging question. - Ray White - 01-04-2019
Thanks David. I will try that and report back. Not being very electrically minded I wouldn't have thought you needed to disconnect the earth wire and check between that wire and the terminal that it was connected to.. I checked that terminal before and there was nothing there. Since then, however, the contacts have stopped opening at even a very slow tick over so perhaps if I do as you say I will find the short.
RE: charging question. - David Stepney - 01-04-2019
If you do get stuck, I have a contact who overhauls Seven electrical instruments including cutouts. He is Trevor Fawcett and his email is "trevazit@hotmail.com". I bought an overhauled distributor from him and was sufficiently impressed to get him to overhaul my existing one as a spare.
RE: charging question. - Ray White - 01-04-2019
Thanks David. It's good to know someone like that. I have just checked the earth terminal and it is not showing anything. Perhaps I need to have the engine running with the contacts closed?
The spring is very weak and looks feeble compared to pictures of others I have seen on line. I wonder if I should experiment with a slightly stronger spring? One end of the spring is soldered on. Is this correct?
RE: charging question. - Ray White - 01-04-2019
SUCCESS!!!!
I had been worried that the spring was unsuitable. It was far to weak and had been soldered at one end ( I presume to stop it falling off!) I have replaced it with a slightly heavier one and it works perfectly. It is not too strong to affect the contacts from closing but assists the reverse current to allow opening at a normal tick over.
Thanks to everyone for their advise.
RE: charging question. - David Stepney - 01-04-2019
Just looked at mine, which is a CF3 cutout and the spring fits around two small lugs, one on the solenoid frame and the other to the end of the moving points arm, so I would surmise that one of the lugs has broken off.
It just could be that the spring, out of weakness, maladjustment or detachment now doesn't have the pull to overcome whatever residual EMF remains in the solenoid.
There is no point in testing the solenoid with the engine running and the points closed; both coils will be energised.
Trying a slightly stronger spring might be an idea. After all, there's nothing to lose by trying.
Just noticed your latest post which you obviously put up whilst I was composing mine!
Excellent news! Happy motoring!
RE: charging question. - Ray White - 01-04-2019
Thanks David. I believe the place who "restored" the cut out (in the Peak District) has gone now. I also had problems with a starter motor they had messed about with. I have made a note of your contact if I should need someone in the future.
Happy motoring to you too.!