300k miles on the '03 Jetta and this is the first time (I think...) that it's let me down.
About 6 weeks ago, 4 blocks from home after sitting overnight, cool start (60F) the car shuts off, just like you turned the key off. Cycled the key and it fires back up and no further issues until Friday when leaving work.
It was about 40F out and I rolled the key over and crank, crank, crank no start. Try it again and noticed no Glow Plug light. Try it a few more times and get it to start and it dies, couple more times and it runs fine the 24 miles home. Forgot about the issue over the weekend, went to go to work this morning and no Glow Plug light, no start.
Pulled 109 relay, popped the cover off, looks brand new inside, contacts clean, etc. Re-install - can feel it click and can manually hold it closed, still no Glow Plug light and no start.
Take the TT to work, get home tonight, review the wiring schematics, find nothing amiss, fuses 32, 34 and 43 are good, have power when the key is on, 109 clicks like it did before, car fires right up.
So...now what? I've got no problem getting a new 109 relay but until then I'll bring a jumper with me just in case.
No Glow Plug light and sudden engine off seems like 109 and this agrees with the schematics, however I can't make sense of why it wouldn't start this morning with the relay engaged.
Thoughts?