Tail bulbs illuminated on dash panel and glow plug light is on

Power is supplied to the instrument illumination by the "TAIL/ILLUM LIGHT" fuse, Fuse #4 (15 Amp) located in the dash fuse block under the left side of the dash. This fuse provides power for both the primary and secondary sides of the TAIL LIGHT relay. The Combination (Headlamp) switch provides a ground path for the primary circuit of the TAIL LIGHT relay. When the primary circuit is completed by the Combination switch, the secondary contacts close and provide power to the tail lamps as well as to all of the instrument illumination bulbs. The ground for the instrument illumination bulbs is a variable-resistance circuit which is controlled by the illumination controller. The final ground for both the combination switch and the illumination controller is Ground G302, located under the center console.

you need new bulbs in tail lights one bulb in each side has two elements one works brake other works running lights the elements in the bulb for tail lites are bad . so just replace bulbs. hope this helps.

the glow plug relay is a little black box normally located in the fues box, the relay regulates power to the glow plugs, if the relay is not functioning correctly the plugs will not heat enough or, you will have to allow a longer time to let them heat up, it acts like a switch as such, when you turn on your ignition it switches over to make a contact inside, which inturn starts the heating prosess of the glow plugs when they are at the correct tempreture or the onbored computer detects they are it then switches back , without it , say just using a fuse instead, your glowplugs will just get hotter and hotter till they melted, and no you dont have to change the glow plugs hope this helps, ime not good at explaining stuff in writing lol

your glow plug relay is going out you need to replace it.

i dont think it will hurt it, you might just be dealing with a loose wire

very common for the harness that plugs onto the glow plugs to have too much resistance it will still work but will set codes

Despite what you may read from other comments....The glow plug light is simple a multi function warning light and IS among many othed things in fact used to warn of brake light and brake light switch failure. Therefore it can NOT be treated as glow plug problems only.
I have worked on V.W for many years and have encountered this problem many times. You should get the OBD codes read. This will reveal the exact problem...and there may be more than one
You can contact your V,W agents if you wish and check to see if I am correct.
Best of luck
John

this means you most likely have a burnt out glow plug or glow plug timer control or both

Depending where you live if the temp. is over 45 degrees F the glow plugs shouldn't be needed for the engine to start. Have you ever had the check engine light come on? Your problem is probably not in the glow plugs.

on some diesel engines the glow plugs will cycle after the engine is started. it does sound like your glow plugs are not all working that would cause the hard start and excessive smoke when it does start.