How long are the glow plugs "ON" for on the 7.3L?
Do they go "OFF" as soon as the engine is cranked or after the engine is running?

...What yr/mk/model?

..They have had numerous TSB's on the harness' and connectors having problems due to heat...

...The glow plug light is a "wait to start light"...When it is at a certain temp it will go out and you are ready to start the diesel vehicle...It takes longer when it is cold out than when it is warm...Cold weather maybe as long as 30 seconds but, when already warmed up in warm weather may only one 1 second...

2001 7.3 van.

But to my understanding, the glow plugs are still on even after the WTS light goes off. Is that correct?

This isnt for diagnosis or anything, my van is fine. I guess I could go and do a VOM check on it but I was just curious.

EDIT - quote from TDS:
The WTS light goes off after roughly 20 seconds (depending on conditions) and the glow plugs can stay on for up to 2 minutes.
http://www.thedieselstop.com/forums/1811145-post5.html

...I'm hoping you will find some answers here...
http://www.helium.com/items/982577-troubleshooting-and-repair-for-ford-73l-powerstroke-glow-plugs

....Not your yr/mk but has some good future info for the FICM...(page 4)
http://www.alliantpower.com/pdf/APTB-0109R1-watermark.pdf

bookmark this page...
http://www.thedieselstop.com/forums/gtsearch.php?cx=partner-pub-7865546952023728%3A7vm55nelen8&cof=FORID%3A11&ie=ISO-8859-1&q=glow+plug+always+on&sa=Go#1279

the glow plugs can remain on for up to 5 minutes depending on EOT, ECT and ambient air temp.

But does it go off as soon as the engine is started?

But does it go off as soon as the engine is started?

No. Your WTS idiot light can remain on for about 2 minutes and the glow plugs can stay on for an additional 2-3 minutes after the engine has been started.

Okay thanks! Thats what I wanted to know.

If you want, I can get the specifics when I get home from work.

But if you hook up a real volt gauge, you'll see your voltage drop to about 10.5V before cranking. It will then drop to about 10V during cranking and jump up to about 11.5V engine running until the GPR cycles off.

Just some food for though: The glow plugs pull about 1000W, the intake heater pulls about 800W, the starter draws about 1200W and your block heater is about 1500W.

Thanks but you dont need to go through all that trouble - I was just curious when the glow plugs go off, and now I know ;)