[Vwdiesel] Glow plugs

[LBaird119 at aol.com]

  Sounds like you have a "slow" relay.  That's about right for maximum 
glow time.  As Roger stated, it all depends on temperature BUT with 
all/most slow relays, the time variation is only on the light on your dash, 
if you don't turn the key and start the car, the glow plugs will always 
get the maximum time from the relay.  Fast relays do things differently.  
Some/all come back on after starting, for a brief interval. They may cut 
out at the light time as well but I don't think so. Never really bothered 
to check.  :)
  If you're running off brand or fast plugs with the slow relay then they 
will last less time than a good set of Bosch.  Since you need a whole 
set of glow plugs, it might be a good time to "upgrade" to the fast plugs 
and relay.  If your replacements are brass behind the nut threads then 
they're fast.  Silver is slow.
  These aren't like a Chevy where a bad controller causes plug failure 
all around, and low voltage keeps the plugs on full time.  REAL handy 
during an alternator failure!  They CAN stick on full time which will 
shorten life but yours doesn't sound like it's doing that.
     Loren