Golf 3 TDI won't start: Troubleshooting guide

Hello,
My Golf 3 TDI with 90 horsepower, manufactured in October 1996, won't start anymore!
'The engine is turning, but the preheating indicator light is not illuminating fully. I have already replaced the ignition switch, but without success. The second key also doesn't work. This error has occurred multiple times: after repeatedly turning the ignition key, the car eventually started.'
Now, it won't start.
Perhaps someone can help me?
Tom

Quote:

The preheating indicator light is not illuminating fully,

The TDI no longer has a "glow plug check light."

The glow spiral is essentially just a motor information light.

When you turn the ignition on, the lights come on briefly and then go off again.

What do you mean by "not fully" illuminating?

m;

It could be any of those things right now. A defect in the WFS (water flow sensor) is likely. It could also be a worn crankshaft. The boss says running a diagnostic test will provide clarity.

Best regards, Holger.

The filament is not glowing at full brightness; if the error hadn't occurred, the lamp would have been 'normally bright,' but now it's 'glowing dimly.'
Best regards,
Tom.

I'll try using relay 109.

momolea wrote:

I'll try using relay 109.

Good idea, chance of success ~ 95%.

The miracle relay is installed, and now the car is working again.
Thank you very much .
Tom

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Report:
My Golf III GT TDI suddenly stopped starting one day.
There was voltage, the starter motor was running, but the engine wouldn't start like it usually does after 3-4 attempts. I then tried starting it for longer periods several times - without success.
Then I noticed that the preheating indicator light wasn't coming on at all (not even briefly, as it usually does). I remembered the preheating fuse in the engine compartment from my old Golf I GTD days. I checked it with a multimeter - it showed continuity, so everything seemed okay.
That's when I reached the end of my knowledge. I had already pictured having the car towed to the workshop in my mind – until I had the idea to search the internet. I had already found a lot of things for my motorcycle (Africa Twin), such as a workshop manual for download – so why not find something similar for the car too?!

While searching on Google, I quickly came across this top-rated board. With patience, using the board search function and constantly refining my search queries, I repeatedly found references to "Relais 109." The rest, as they say, is history.
I disassembled and opened it - visually everything looks okay, no cold solder joints are visible, and everything else seems to be in perfect condition. Since I didn't have any other ideas, I still ordered a replacement: 11.37 euros including VAT. I installed it, preheated it, and *whoosh* - the engine is running like new.

So, a big thank you to everyone who writes and helps here, and especially to the forum administrators.

I'll definitely be coming here more often now...

Hello kleffx.

kleffx wrote:

With a calm approach, using the board's search function and constantly entering new search queries, I repeatedly found references to relay 109. The rest, you can imagine. I disassembled and opened it - visually everything looks okay, no cold solder joints are visible, and everything else seems to be in perfect condition. Since I didn't have any other ideas, I still ordered a replacement: 11.37 euros including VAT. I installed it, preheated it, and *whoosh* - the engine is running like new. So, thank you very much to everyone who writes and helps here, and especially to the forum administrators.

Thank you - it's also nice to read something like that again .

I'll add to the story about the frequent errors -> the preheating indicator light might be dimmer, etc.