Helo, In troubleshooting some FI issues, I removed the black diode that is on the Jetronic relay board below the antenna without noting its orientation. Would anyone know off-hand if the side marked "51 Batterie" goes to the spade connecter with the double wires or the single ? Many thx, Oleh
Assuming you are referring to the ECU, the diode anode is connected to the connector pin 3 and the cathode to the connector pin 2. Customary marking is to print a ring around the cathode end. If you had the diagram as I do, (http://www.ferrari308gtbi.com/) you could have found it yourself. Image Unavailable, Please Login
Many thanks, that is the diode in question. Unfortunatly I cant tell the cathode end as there are no markings other than one end marked as "battery" nd the other as "generator" An idea which one would be which ? Thx Oleh
Is that diode so large that battery and generator are printed on it...or is the printing on the circuit board? Some ginny probably took the original Italian drawing and plugged it into the dictionary getting a bad translation of battery and generator. I love circuit puzzles and will get answer.
Paul: The diode looks like a large inline fuse holder, which is what I thought it was initially, thus my carelessness in removing it. Its all black, cylindrical and in tiny writing on each end it has "battery" and "generator" inscribed (yes, in Italian !). There is a sloppily painted white dot on one end (either that or its bird crap that came in through the antenna), I am thinking maybe that is the cathode end but I am hoping to nail it down further before I stick in and risk sending current the wrong way. I will post a pic later. Thx, Oleh
Oleh, I would suggest you use an ohmmeter to establish which end of the diode socket is at pin 3 (anode) and which is at pin 2 (cathode). To establish which end of the diode is the anode and which the cathode, I would make a simple test setup, find a small 12v lamp bulb and battery (or use the car battery). Make a simple circuit connecting the 12v battery and a 12v lamp. Make sure the lamp lights. Then insert the diode between the battery (+) and the lamp and if the light doesn't light, reverse the diode. When the lamp lights, the diode anode is at the + terminal. And that's the end that goes to pin 3 of the ECU socket. This test setup will not harm the diode.
