[Vwdiesel] slow glow plug relay, no glow light when engine is warm

Marciano Pitargue mpitargue at gmail.com
Fri Sep 5 12:21:16 PDT 2014


It never rains in San Jose, CA.  But last winter, it did a bit, and my fuse
box got wet due to a poor seal of the windshield.  (Fixed that I hope.)
So, I ended up changing out the (original ?) crusty metal bodied (slow)
glow plug relay in my 1980 caddy with a plastic bodied glow plug relay
replacement.  Supposedly, this glow plug relay is for the slow glow plug
relay circuit that were on the 1980 vw diesel vehicles.

Now, when the engine is cold, like first thing in the morning, I get the
nice warm glow of the glow plug light.  However, when the engine is up to
temp, no glow plug light, hence hard starting if the truck sat for about 30
minutes.  Before the fuse box wet event, it always used to light up no
matter the temperature of the engine.  And it seems the glow plug light
accurately tracks the power to the glow plugs.

Checked the grounds for the relays for corrosion.  They seem clean.  One
thing I noticed is that when the glow plug light doesn't light, if I unplug
and plug in the (new) relay, sometimes the glow plug light lights.  I
suspect that that the glow plug relay isn't correct for my slow glow plug
relay circuit.  Or maybe I missed some ground points (I found 2 circular
fobs where a bunch of brown wires connect to.)

Any advice from the group to address this issue?

Thanks in advance.

Marciano, driver of "slo-mo smokey"


More information about the Vwdiesel mailing list