Glowplug and fuel cutoff connection?

[AntonUK]

Hi everyone I have a very annoying problem with my A3 JettaTD.

It all started a while ago when I had problems with glowplugs not turning on in the mornings and the car not starting when its warm. I went to a local VW Audi parts shop and the guy phoned one of him technicians about the problem and he told me that it was the glowplug relay. He also said that fuel cutoff circuit also passes through the relay which explaines why the car sometimes doesnt start even when its warm.

So I bought a new relay and everything seemed fine until about a month later. The same problem has arrised slowly until now when its nearly impossible to start the car when its warm. The glowplugs usually turn on in the morning or if they dont, I turn the ignition off then back on and the glowplug light comes on. Then when you drive somewhere and stop its most likely that the car will not start back up again.  The only way I found to start they car is to move the wires around behind the fuse box.

At first I blamed the relay but then again surley the relay would last a lot longer than a month. So Im thinking its a bad contact with some wires at the back of the fusebox in relation to the glowplug circuit (if Iv been told correct that the fuel cutoff passes through the relay). Im also currious why my glowplug light only comes on after turning ignition on the second time??

If anyone could help me round this problem or has any circuit diagrams to help me pin point the bad wired I would be very gratefull!

Thanks everyone

[BlackTieTD]

i think you're on the right track. if you wiggle the wires behind the fusebox and it seems to temporarily fix the problem... then there is probably a bad connection back there somewhere... i experienced this with the turn signals.

if you can get back in behind there... trace the wires and see if you can find any bad connections. this would be a good time to do some obligatory VW wiring clean-up overlooked by the factory  :lol: