S1 Dynamo to Alternator Upgrade

[Greg Shilton]

Please can I have some help and some opinions? I am thinking, as it is quite often a common mod to a classic car, about upgrading the dynamo on my S1 1.3S Sport to an alternator. I know the S1 and S3 Fulvia’s came with an alternator and would like to know how easy it would be to upgrade my electrical system? Would it be a case of using the alternator from the later series Fulvia or could I use any alternator as a replacement, I guess with an onboard regulator, and what would it entail to do this conversion on a Fulvia?

Many thanks,
Greg.

[Greg Shilton]

S2 and S3 Fulvia's came with the alternators, sorry.

[Walter van Gruythuysen]

I did the same a couple of months ago. I use my coupe as daily driver and have to survive traffic jams in Holland with it. An alternator performs much better at low rpms. The electrical update is a piece of cake. You simply connect the wires to the new regulator and add an extra + to the battery, to be sure not to overload the existing one.

The mechanical conversion is quite complicated:
- Your fan is driven by the dynamo belt. In my case that problem was solved a couple of years ago by an electrical fan. You will need a 2nd series radiator for the supports.
- Your petrol pump will be an obstacle for the alternator. You can solve that by an electrical pump or maybe by fitting a 2nd series pump.
- The support bracket on your block is in the wrong position for an alternator. It took me quite some time and trial and error brackets to make the right one. You will also need the bracket on the waterpump from a 2nd series.

You can use almost any alternator. The only restriction is the diameter since the carbs will be on top of it. I have a ducellier from a 3rd series and it works fine.

But when I have to give an honest advice: Unless you have a very good reason to convert, as I had, leave the dynamo as is. You can improve it with the regulator as described by Huib on May 14th in this forum.

Walter

[Thomas]

note Zagato's have different radiators than coupe's. Presumably a 2nd series radiator will not fit in your S1 Sport.

[Greg Shilton]

Yes, I've noticed about the different radiator while I've been having a quick look and I'm not sure if the coupe radiator will fit. Maybe it is easier to stay with the dynamo for now?

When I asked the alternator question I had an intermittent problem with the headlights, after cleaning contacts on the switch etc, they seem to be more reliable, but when I turn them on when the car is at low revs/idle it tries to cut the engine out! I’m guessing that could be due to the dynamo not producing enough current to charge the battery correctly. Or am I likely to be wrong on this? Sorry I am new to all this stuff.

Anyway thank you for the replys Walter and Thomas.
Greg.

[Ed Levin]

Greg,
Check and clean the grounding for the lights. A lot of electrical problems like that come down to a bad ground (earth).

[Huib Geurink]

The main beam does need an extra relay. The current for the main beams goes through the switch on the dashboard AND through the change over relay. You need to wire an extra relay which is driven by the main beam output of the change over relais. This has nothing to do with the engine stalling when switching the lights on.

Did you check the wattage of the bulbs? If duplo it should be 45/40 watts. If H4 it should be 60/55 watt. Putting in higher wattage is totally useless and may in addition overload the dynamo.

Dynamo's produce less current at idle than alternators. I drive my S1 coupe about 50.000 km per year and burned 2 voltage regulators per year and 1 dynamo. Both caused by the bad quality of the imitation regulators. I always have a spare dynamo and regulator in the boot. The other S1 coupe which has the last new original Bosch regulator does not have the problem.

When I burned an other regulator a couple of weeks ago I was again looking into the problem and about to decide between changing to a modern alternator (definitely not an S2 or S3 alternator which still have plain silicon diodes instead of Schottky diodes) and designing and building an electronic regulator. Fortunately I found an original Bosch electronic regulator for 30 amp dynamo's which costs next to nothing. It is fantastic. The dynamo light goes out quickly and the charge current rises very rapidly with revs. Really the peformance goes way up and I expect the life time also to improve as regulation is done by changing the field current and not by chopping output voltage.

I mentioned the regulator a few postings down. See
http://www.viva-lancia.com/lancia_fora/ ... 738&t=4738

I recommend everybody with an S1 car to put in the electronic regulator yesterday and forget about the conversion to alternator.

It is also a good idea for Fulvia's with 4 head lights to rewire the headlights that only 2 are on at the same time if they are converted to halogen. If the head lights still use 45/40 watt bulbs than you are ok if 4 head lights go on at the same time but it is still better to convert to H1 55 watt main beams and switch off the outer ones when on main beam. Modern Surface Complex 5 3/4" units combine long range with excellent width of the beam an good side of the road lighting too. Never use bulbs using more than 60 watts.

[Greg Shilton]

Cheers Guys,

Huib I've just had a look at the voltage regulator posts and can you confirm if this is the correct regulator?

http://www.justaircooled.co.uk/product. ... t=0&page=1

I'm stumped by the light issue, I will check the bulb wattage, but the engine just tries to cut out when the headlights and full beam are turned on. Any ideas?

Thanks,
Greg.

[Huib Geurink]

That picture shows the original electromechanical regulator. Not the electronic one.

I have just come back from a 3 day trip to northern France for organising our yearly Fulvia rally. Please, register guys for the trip. Hotel accomodation is limited.
I did the trip with Elena, one of my 1967 rallye 1.3 coupe's. She has the original dynamo and Bosch electromechanical regulator. Headlights have been converted to halogen. 55 watt H1 for the inner ones and 60/55 watt H4 for the outer ones. I just tested to see what happens at idle when switching all 4 headlights on and off. Does not make 1 rev of difference.

Let's think along the following line:
1 at idle the dynamo is not yet delivering any current. Check if indeed dynamo light is still on.
2 all current is supllied by the battery.
If the engine tries to stall it is not the effect of too much power drawn by the dynamo but probably too low voltage for the ignition.

So, please, check what the battery voltage does when switching lights on and off. If it drops below 12 volt you have a under charged or defective battery.
If the battery voltage remains above 12 Volt the next step is to check if there is excessive voltage drop in the wiring / fuses / contact switch.

[Greg Shilton]

Cheers Huib, thanks for your help, I will investigate.