Ignition barrel question

[DavidHill]

I have an odd fault on my B20.  on connecting the battery the ignition warning light comes on without the key in the ignition. on putting the key in the ignition and turning the key to "on", the light goes out,  the fuel pump engages and the car starts on the starter button.  so the opposite of what should happen with the ignition light!  I suspect the ignition barrel has a fault internally...has anyone taken one apart?

[williamcorke]

Hi David,

Has the car always had this symptom, or is it a new thing?

I have a couple of early ignition switches (should be the same as yours) that are currently apart, so can provide photos or you can come and have a look at them if you want to.

W

[DavidHill]

Hi William,

yes its just happened...i recall moving the key around a bit more than usual when i last drove the car...so think something may have occurred then...if you could send pictures of the inside of one that would be really useful!

cheers
David.

[chriswgawne]

From memory, at the opposite end to where you insert the key there is a rotating metal peg which fits into a plastic part which carries the contacts. If the plastic rotating part is worn or broken then you might get the effect you describe.
The ignition switch itself  is easily dismantled for inspection and if you need any internal bits I imagine I will have good used examples.
Chris

[williamcorke]

The mechanism is indeed pretty simple and with no 'push switch' function for starting, unlike later versions.

The plastic part Chris is referring to (resin/bakelite? and brass) is rotated by the lock barrel so that the brass plate on the back part makes and breaks circuits between the 3 sprung terminals. There is a spring and ball bearing detent on the other side of the bakelite/plate with two end positions that the ball can locate in, at 90 degrees to each other, presumably to stop the accidental rotation due to vibration once the car is running.

sloppy location of the plate on the drive peg 'D' on the end of the barrel is, I agree with Chris, the most likely cause. The rest of the parts of the unit are much less likely to have age-related material issues.

[DavidHill]

Hi William,

thanks for the pictures,  as always with Lancia my barrel is slightly different....see pictures. it seems to be ok.  the plastic/bakelite circle behind the three prongs is broken at the top, but that must have been like that for some time and worked well as there are no pieces of it in the barrel...

[DavidHill]

hmm, have not found the issue yet.  I took the ignition barrel completely apart and all seems ok.  The symptoms continue though:

1. on connecting the battery with the ignition off, the ignition warning light immediately comes on and stays on
2. on turning the ignition key to on - the electric fuel pump runs and the ignition warning light goes out
3. on pressing the starter button the B20 starts and runs well.

on measuring the voltage at the battery with the engine at idle i get 12.5V - which is a bit low - maybe there is an alternator issue? on taking the revs to 1300rpm i get 13.5v at the battery.

On measuring the voltages at the ignition barrel - with ignition off i get 12v at position 30, 0V at position 54 and 2.2v at position 15 (i assume 15 should be 0V too, so 2.2v is a bit odd?)
On measuring the voltages at the ignition barrel - with ignition on i get 12v at position 30, 12V at position 54 and 12vv at position 15

any thoughts / suggestions??

[lancialulu]

Normally Aurelias are fitted with dynamos which do not provide a charge at low revs.

[DavidHill]

yes of course, but mine has an alternator fitted (by Peter Harding some years ago

[williamcorke]

I had one of those split pulley alternators on my 6th Series car years ago, and the circuit board (?) in it malfunctioned, causing all kinds of mayhem with massive battery drain and worse. I'd look there next if I were you. Perhaps swap in a known/working dynamo and see if the ignition light issue disappears.

[lancialulu]

If it is a "dynator" (alternator in Dynamo body) it may have cooked the regulator/rectifiers

[DavidHill]

Hi William,

yes i think it is the alternator...as when i first connect the battery all is well, but i can hear a faint ticking sound and then the ignition warning light comes one etc...so i think there is a fault in it...next step is to remove and investigate as you say....not an easy job!

[chriswgawne]

Sounds like the alternator.
I fitted one to my 3rd srs B20 when I was racing it and  had no issues but this was after a Magneti Marelli voltage regulator issue with the dynamo on the car. I couldn't find anyone to repair the voltage regulator back then  ( and I still haven't found anyone here or in Italy)  and I didnt have a good spare voltage regulator.
After fitting the alternator I heard of a couple of other old car owners who had fitted  alternators with consequent problems of overloaded cables etc so I decided to try to stick to OE equipment. The saving grace today is that its possible to economically and reliably convert the insides of a faulty OE regulator to solid state as per Tim Heaths excellent article in Viva Lancia whilst keeping the reliable dynamo and using the OE voltage regulator housing..
Chris

[will]

I think Chris is right its best to fit OE equipment if possible. On the Appia i fitted an alternator and it blew the battery up and my Tom Tom.
I was told that you need a heat shield if you replace a dynamo with an alternator.

When I bought the B20 it had Bosch regulator that soon gave trouble another Aurelia owner suggested I fitter solid state unit
in an old Aurelia regulator he had just fitted one and was very happy. I bought mine from Classic Dynamo & Regulator conversions.
I sent them the old regulator and dynamo they fitted the sold state regulator in the old case and checked the dynamo worked.
The big advantage solid state regulator produces amps at low revs which the old regulator did not.
The B20 dynamo only produces 20-30 amps but with LED bulbs you don't even need that. 

[DavidHill]

I do still have the old dynamo, so when i get the alternator off the car, will take them both down to J Morgan and Sons in Dorking...they did a very good job rebuilding my Aprilia's dynamo and fitting it with a solid state regulator and will see what they recommend.

Ref removing the alternator, does anyone have a diagram of how it is held tight in place?  I have removed a split pin and then a hollow elongated nut from the top of the dynamo housing. This revealed a long rod going into the housing - i guess this clamps the dynamo somehow...any advice on how to loosen the alternator as it is still solid in the housing?