I'm having cold starting issues with my mk2 2007 vrs diesel estate. I've been reading the forum's many thousand posts on glow plugs etc. I've had the glow plugs changed, to no avail. I now want to test the glow plug relay, but I can't find it... People seem to talk about relay 109, but I don't seem to have one? I've looked under the dash, and in the under bonnet box.

Could someone point me in the right direction.

Many thanks,

Matt

I think it might be under the fuse box in the engine compartment. don't know for sure or how to ID it better. HTH

Thanks, I've found a PDF online for a Jetta, Bora and Golf which looks like it show the procedure to get to the relay (or "automatic glow period control unit J179" as it calls it). Once the snow has cleared a bit, I'll investigate; if it turns out to be right I'll see if I can post a link to the PDF for future reference for others.

It does indeed show the relay as being under the fuse box, looks like you need to remove the battery tray, then slide it out.

Cheers,

Matt

Ok,

Have had a chance to take a look for the glow plug relay / control unit; and I found it...

These instructions are from memory, and are for my 07 vRS Estate (your mileage may vary)

You need to remove the battery, and the front ½ of the battery shroud, it has 2 small clips at the bottom and then slides upwards. The relay is located under the under bonnet fuse box, and slides out (towards the engine), the relay can then be unclipped. My relay has the following part numbers on it: “0 281 003 038”, “905”, “038 907 281 D” and “RB6”.

Hope this helps anyone else looking for their relay. I've ordered a new one, but as I removed the battery it was showing signs of bulging at the sides so I'll be replacing that as well when the relay arrives...

Matt