Expert: Roland Finston - 1/30/2012

Question
Hope you can help. I have a Chrysler Grand Voyager 2003 plate. Had problem firing after start and discovered that all heater glow plugs were u/s. Kept draining battery trying to start.
    All four heater plugs have been changed successfully.The car still wont fire( problem of course on cold start.when fired using easy start and car warm all is ok. problem only occurs when freezing or cold in the morning). Starter motor is turning, glow plug light is coming on for a few seconds. However it has become apparent that when checking for power to glow plugs when ignition is in first position , there is no power supply to each of the glow plugs.
I have checked the fuse under the bonnet on the left hand side and is ok. Is there any other fuse I have missed or any reason why I have no supply on turning key to first position? My local mechanic is at a loss as to why the plugs don't have this power supply to heater plugs on start.

Answer
Hi Grahame,
If the glow plug control circuit in the diesel is identical to that in the gas engines then I would believe that you may have a problem with either the camshaft or the crankshaft rotational position sensor. In order to circumvent fire in the case of an accident the engine controller requires that there be evidence that the engine is running for there to be power to the heater/glow plugs and to the fuel pump.
I would do a fault code readout to see if there is a 4-digit number stored in the engine controller by turning the ignition switch:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer windoew of the instrument cluster to see if the kilometer reading changes and shows such a number preceded by a P. Let me know and we'll go from there.
If there is a sensor signal absent then the controller will cut the power to the plugs because it interprets that it could be an accident that caused the engine to stop rotating. Let me know what you find. The other possibility if you never 'see' power to the plug relay is that one or the other of 2 fusible links that are in series between the battery and pin 1 of the glow plug relay socket is blown.
Roland
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