[Vwdiesel] Marks LED GP cct works...I think

Smith, Michael Michael.Smith at rvh.nb.ca
Fri Dec 31 12:04:12 EST 2004

Mark et al, 

I found a few minutes to wire up your circuit here on the bench and using
just a light bulb (instead of a real glow plug) and
some hookup wire, an LED (with 1k resistor in series) a big battery and a
biga$$ blocking diode, I got your cct to work.

Whether this will work in situ, I can't say 100% for sure, but it sure looks

Here's how it worked for me (at about the 2 Amp level and only 1 LED....and
1 lightbulb(GP)
Turn ignition switch on....GP's come on and heat. (no LED's) 
Timer kicks in (out?) and GP's turn off.....4 LED's come on as soon as GP's
go off indicating you have good GP's.
LED's will STAY ON, so you will need to rig up a switch to turn them off, as
ultimately current is going through your
GP's all the time. admittedly it's pretty low milliamp levels, but

I haven't yet had time to rig up a parallel cct with another bulb(GP) and a
2nd blocking diode, but so far don't see any problems.

Will report any future findings to the list.  Email Mark the Miser (or me)
for the .jpg diagram of his cct.

I am thinking a small toggle switch running a 4Pole relay to control all 4
LED's at once instead of 4 toggles.

Mike in NB (@ work)

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