I originally posted this on TDIClub...
I was driving my Jetta, and had to stop for an intersection. I hadn't completely fixed the shift linkage, and something else wore out in it, so I was doing second gear starts.
Anyway, I tried to do one, and failed, because I didn't rev it high enough. So, I tried starting the car again. It acted like there was VERY little power available, and was slowing down the more I tried, even after letting it sit.
However, accessories had plenty of power when I wasn't cranking.
The alternator seemed to be charging.
This is more a rant than anything, but...
Tonight, I'm gonna check to see if it's the starter or something else.
Edit: Just got an e-mail:
I made it home with no problem. Turned off the car, tried to start it - started right up. Turned it off again, tried to re-start it - started right up. Jetta's a naughty girl. Going to bring the truck, anyway.
Check the wire going from the battery to the starter motor. Positive, and ground. Maybe loose -- works sometimes but occasionally not?
I'm dealing with this exact same problem right now. My dad and I took a reading at the battery and then at the starter and found a much lower reading at the end of the positive cable at the starter. I'm going to get a new one and check the readings I'll let you know if this works.
Out.
Greg
i had the same problem with my caddy. It could also be the ground cable. the fix only came when i watched under the hood while my s.o cranked it. turns out the ground cable from the batt was making good enough connection for everything but the huge draw created by cranking the diesel. the block to batt ground had a good connection (#6) wire and got so hot it melted the insulation. replaced the ground cable and it cranks like new. good luck.