[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]
On 21 Nov 2003 at 12:22, Mike Wodkowski wrote: > > Turn the engine off. > > > > Remove all the wires from the D+ and DF terminals on your new generator and > > push those wires out of the way. Make the following resistance measurements: > > > > What is the resistance between D+ and ground on the generator? > > Zero It's actually slightly above zero, but still less than 1 Ohm, so this sounds fine. > > What is the resistance between D+ and DF on the generator? > > Infinity This should be 3-4 Ohms. The field windings of the generator are connected directly between these 2 terminals, and their wires should be soldered directly to the underside of the terminals. If your field winding is open the generator will never generate. Sound familiar? Double-check this (use the R x 1 scale on your VOM), and if it still stays high, return it for a better one. This was a rebuilt, I assume; who rebuilt it? You could try looking inside the generator to see if you see any signs that a wire has come loose, broken, burned thru or that a field winding is charred from overheating. You can see the field windings from the brush holes and from the air hole. I'm concerned that your string of problems all have a common cause which we haven't fixed yet. One thing that might explain all of these problems would be that the DF wire has an occasional short to ground somewhere between the DF terminal on the generator and the DF terminal on the VR. If this happened, it would turn the generator on full blast (this is called "full fielding" the generator, often done for testing) and would burn out the field windings if driven this way for a few minutes. The generator light would probably be on during this process. You had a second wire connected to one of the generator terminals at one time. I believe you measured that as being grounded at one time, although it cleared up without explaination. You should be just running this generator with one wire on each terminal (D+ and DF) but there is a separate brown wire that runs to a ground screw on the generator body. If you count that wire, that's 3 wires total to three connection points. You should check where the wire disappears into the wiring harness, and where the wiring harness goes into the bodywork. Then check the other end at the VR. One possibility at the VR end would be that the seat belt buckle had fallen against the VR and shorted the DF terminal to ground. You should also inspect the DF wire for scrapes and breaks in the insulation at that end. -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org