1993 Passat TD glow plug problem.

[TTH]

Hey all,

I tried a search for glow plug problems relating to the B3 Passat, and searched some of the repair manual pdf files on the web, but couldn't find what I need.

The glow plugs quit working after I swapped a used cylinder head on.  The light on the dash will not light up, and I don't get voltage to the glow plugs when I key on.  Under the dash, I checked relay location # 12 (bottom right) for continuity.  Position 87 has continuity to the glow plugs, position 30 has 12 volts all the time.  I would imagine that position 85 supplies switched ground to the relay from .  The relay itself works when grounded (I pulled it to test).

It looks like the problem is that for whatever reason, I am not getting position 85 grounded.  I could really use a tutorial from someone explaining how the remainder of the circuit works, and what to test.  Reading some previous posts, it looks like there should be a glow plug timer (location?) and a coolant temperature switch that provides an input to the timer.

Any help appreciated.  Thanks!

[zukgod1]

Did you reuse the coolent outlet/sensors from your old head or was there one already on the replacment head?

[TTH]

Did you reuse the coolent outlet/sensors from your old head or was there one already on the replacment head?

I believe I used the one that was on the replacement head.  Did they have different sensors for different years or chassis?

[zukgod1]

you could just have a bad sensor,

Try swapping your old one on and see if that takes care of it.