[Britalia]

I replaced the 101 series engine in my Giulietta with a 105 block and had to replace my Lucas generator with a Bosch. I still have the Lucas voltage regulator which was in working order. I polarized the generator by briefly connecting the A and D posts on the regulator and got the expected spark. I wanted to keep the car positive ground.
When I start the car, the generator light stays on, and the voltage at the battery stays 12.8 no matter what the rpm.
I am thinking that the generator is not putting out any voltage/current and I need to take it out and have it rebuilt. Are there any in car tests I can do to verify that is the problem, as removing the generator is not an easy task at this point.
Thanks for any help
Chuck in NC

 

[Tifosi]

Old trick from days gone by: Start it up, then unhook the battery + and see if it keeps running.

If it quits, the generator isn't putting out. If it continues to run, then the problem is likely elswhere.

 

[rogerspeed]

The Glenn's Alfa Romeo Repair and Tune-up Manual reprinted by Brooklands available from Motorbooks has a complete diagnosis section on the generator and regulator.

 

[Britalia]

Thanks for the advice. I am nearly certain that the generator is the problem. Does anyone know where to find replacement brushes, etc for Bosch generators ? Or, does anyone know a reliable rebuilder that I could send it to.
Regards
Chuck in NC

 

[Tifosi]

Likely any shop that has the Bosch sticker on the door or front window will have, or have access to, rebuild parts.

Check your yellow pages under auto repair. They generally will advertise if they are Bosch certified/authorized.

 

[Britalia]

Thought I would give you an update. I had the Bosch generator rebuilt. I polarized it for positive ground and installed it. Still no voltage charge to the battery, and the generator light is on. After some additional on line research it appears that a Bosch generator and a Lucas voltage regular are incompatible due to a difference in the way the field current is controlled. The Bosch generator field circuit is wired differently and can only be used with the Bosch regulator.
I have decided to removed the Lucas voltage regulator, convert the car to negative ground, and use the Bosch regulator. Hopefully this experience will save others from similar problems. Anyone else agree with this analysis ? Thanks for your help.
Chuck in NC

 

[Mikes4C1300]

Old trick from days gone by: Start it up, then unhook the battery + and see if it keeps running.

If it quits, the generator isn't putting out. If it continues to run, then the problem is likely elswhere.

Darren, thanks for posting this now-nearly-two-year-old tip. The engine in my 105 died graveyard dead when I pulled the battery lead. I wasn't sure if the problem was with the generator or voltage regulator or how to test either. I guess every forty years generators need a rebuild, like it or not!

Mike Hollinger
Atlanta