97 Passat, quick glow plug cycle, can't find Glow Plug relay

The indicator on the dash and the contact of the relay actually powering the glow plugs are electrically independent. A blown fuse for the glow plugs would have no bearing on the duration of the "please wait" indicator on in the instrument cluster.
An unexpectedly brief "please wait" indication implies that the ECU thinks the temperature isn't so cold as to require a longer pause as the glow plugs are (or should be) heating up. The problem may be an inaccurate temperature sensor not sending a resistance value back to the ECU that corresponds with the actual temperature.

I have a very brief glow plug light at times. I have tracked it down to the relay which I am in the process of replacing.

Check my post for details.

http://forums.tdiclub.com/showthread.php?t=123754

The relay is hard to find. You have to pull down the fuse panel and lying on your back, look up to the drivers side and you can see a relay all by itself. It took me a few tries to find it. It should say 180 on the top.

You may want to first try unplugging the coolant temp sensor to see if you can get it to fire the GPs for the default (long) duration.

yes, if I unplug the clloant sensor the duration is very long every time. That mean coolant sensor is occasionally bad?

Quite possibly. It happened on my parents' A4, it could happen to ours. If you do swap it make sure you have plenty of the appropriate coolant (i.e. G12 if G12) on hand and have the new sensor ready to shove in the hole. A lot of coolant can come out of that hole in a hurry.

I don't have to tell you to do this when the engine is cold, do I?

Understand, and the fact that it has been below ZERO every morning all week I think I have that part covered assuming I dont drive it right before.

2TDIguy said:

yes, if I unplug the clloant sensor the duration is very long every time. That mean coolant sensor is occasionally bad?

Click to expand...

No. When you unplug the coolant sensor the system sees it as very cold and runs the plugs for the maximum time.

I'd try replacing the glow plug relay and using the following sites:
www.vw-parts-direct.com,
www.vwdieselparts.com,
and www.replacement.autopartswarehouse.com to get the dealer priced relay of $134 for about $34 instead. This turns out to be the same relay used for the ECM on my 97 A3 TDI Jetta. The glow plug fuse is under the dash above the relay panel, and is in a large red plug-in housing to receive the same double bladed fuse and the others, but obviously much larger. You'll have to unhook the fuse/relay panel and let it hang down to see it.
Good luck. Jim )