QuestionHello again,
I went ahead and found an new connector for the altinator and spliced it into the existing wires. I double checked the wiring to make sure that I did not swtich the dark green and the green/orange. It seemed to work great until the heat of the day when the fuse blew three times in pretty quick succession (I made it about 50 yard in those three times). The next question I have is, could the new alternator be the problem? I was presented with two options when I bought the new one. 90amp and 120amp. Could the wrong one cause this fuse to pop? I selected the 120amp because I thought with rear air I would need more power. Any other ideas? Thanks a ton!
Jared
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Followup To
Question -
I had to replace the altinator on my 1997 Grand Caravan (Has the 3.3 V6). While replacing the Altinator, the plug that plugs into the back of the altinator was ripped from the wires (stupid altinator is pretty tricky to get out). I spliced it back on, but now the 20amp fuse labeled for Engine randomly pops while driving. Any ideas?
Answer -
Hi Jared,
If you are talking about fuse #12 which is 20 amp and is associated with supplying one of the wires that is connected to the alternator (and when it blows the engine should die, correct?), then I believe that the dark green/orange wire on the plug to the generator is shorting to ground spontaneously due to movement and that it has lost some insulation or is otherwise being shorted to ground. It could be that it is shorting to the dark green wire at the plug due to a faulty splicing job and that dark green wire varies between having 12V on it and having a ground on it (by the action of the engine controller) so that is why it doesn't happen all the time, just randomly. So I would re do the splicing job or get a new plug or somehow fashion new plug(s) for those three wires that were ripped out of the old plug. Another possibility is that you didn't rewire the plug correctly (switched the wires) so that you are by-passing the alternator and whenever the engine controller tries to turn on the field coil, it is just grounding the dark green/orange wire rather than ground the dark green wire. That too would blow the fuse.
That is my best suggestion. If it is not fuse 12 then tell me which one it is, but that looks like the one that would blow if you had damaged the wires at that alternator plug.
Roland
AnswerHi Jared,
The fuse that blows (if is it #12, you still didn't tell me?) powers a lot of things when the autoshutdown relay closes (e.g. when the engine is fired up): it powers the spark coil pack, the alternator field coils (when the pcm asks for juice from the alternator), the up and down stream oxygen sensors and the fuel injectors. I don't know the difference between the current draw of the field coils of the two alternators but it could be that would make a difference sufficient to overload the fuse. If you have satisfied yourself that the two wires that are involved: dark green/orange between the alternator and the fuse and the dark green between the alternator and the power control module are not possibly shorting to ground, then if nothing else in the list of items above has been modified I would suspect that the 120 amp alternator is overdrawing the fuse. You could try a 30 amp fuse and see if that holds. I don't have the official wiring diagrams for the van, just the Haynes, and it doesn't have anything specific about the current draw of those two alternators. If the 30 blows then maybe the alternator field coil is shorted internally and you need to return it, and ideally get the 90 instead.
Roland
