[Vwdiesel] Glow plug intermitancy

[mikitka]

Well I have been trouble shooting a glow plug problem. Seems that when I
turn on the key the glow plugs are not getting 12v to them, so I took the
relay out and it looked ok and when I checked it with a  multi meter it was
ok for the checks that I did. I have talked to Val some on this. The
contacts in the relay look great. When I do a continuity check and close the
contact it gets continuity. I checked the to main post on the resistor and
when it is plugged into the fuse block and it is seeing 12v's.  

 

After messing around with it, I was able to get 10.5v's to the glow plug
fuse on the firewall. The pattery is putting out 12.56v's when I checked it.
Do I have a power loss somewhere and the fact that the glow plugs are not
seeing a full 12v's is an issue?  This last check the relay seems to work.
The GP fuse was getting the 10.5v's for a count of 8 and then it went out.
Does that sound about right.  I couldn't see where the terminals inside the
fuse block were pushed in at the relay connector.

 

I was wondering if the coolant sensor might be coming into play? Could it be
going bad? If it was sensing that the engine was warm then the glow plugs do
not work correct? Or do they still come on but it is only for a split
second?  All other fuse's are good from a visual stand point.  

 

At least it is summer and the jetta starts right up on the cold 75 degree
mornings we have had when I pull the cold start cable out. If I don't then
it takes a few revolutions before it will fire.

 

Nick