I took out my mechanical regulator to install an electronic one. My "helper" took the tape off the wires in the engine compartment while he was "cleaning stuff". He's 12 and he means well, heh...

Anyway, I have 2 wires joined together, one red and one black. Then I have one thin black wire, then I have 2 wires joined together, one brown, and one that looks green (it's kinds dirty back there).

Any help?

It's a 126 engine with a generator in a 69 500L.

Thanks.

Anybody got a close up photo of their voltage regulator? I found a wiring diagram, which I may be reading incorrectly, but it only shows one wire in a position where I have two joined to a common connector.

Here is a scan of the Fiat wiring diagram from my 1969 500L owners manual.
Easier to read if you increase the zoom to 200%.
It is item #29 .

Terminal #30 - Red from fuse box & Brown from Starter motor
Terminal #67 - Black from Generator
Terminal #51 - Green from electrical connector at dash & Brown from Generator

I would make sure you get the brown wires on the correct terminals.

John

Thank you-- that's a lot better than the one I found.

let me take a closer look... before I give bad info. *edit*

Ok, I posted yesterday that I had indeed wired it as your diagram indicated, but then I got to thinking, so I deleted that until I got home and checked the car.

Sure enough, I had the batt/starter & gen wires crossed. Unreal! The b&w diagram I had was too poor in quality to read the terminal numbers, and I don't know... I must have been holding it upside down? Haha. Oh man.

I even ran the car this way-- in just a minute or so, the regulator, the wires to the gen, and the gen itself got so hot it was scary. Smelled like burning and all. I was pretty sure I had fried the new electronic regulator, and doubly sure after I realized it was wired wrong...

Nope! Switched around the wires, started it up, and the light went off. I am so relieved. Thank you so much for posting that diagram!

It's funny, this car. I've worked on VW's forever, and when I hear someone new to VW's ask the simplest questions, I sometimes smile. Well... now I'm that guy! I feel like it's my first time working on a car sometimes, lol. And whatever documentation I do find, is often in Italian...

This car is proving to be loads and loads of fun. Thanks again for your help!

I did the valve adjustment with my eyes closed though. Only took half the time of a VW, lol!

Glad to help out. You may wish to put a voltmeter on your battery with the engine running around 3000 rpm. You should see 13.5 volts or higher, but nothing over 14.6 volts. If you see only 12.5 volts or lower, or 15 volts+ you fried something.
John