Glow Plug light ON issue

208 CDi 2003 Sprinter - Australia

Glow Light always ON issue..

Hi all..
Not long had this 208 CDi - upgrade from a 312D (still in the family).

On getting this van , I noticed the glow plug light always on whilst started. Without pulling the plugs out(have new ones to put in) , I figured I would disconnect the wire terminals at the glow Plug relay.
I did this and the light is still on.

1. How does the system work?

2. What can I do to correct the light ON situation?

I would assume by removing the wiring at the relay , the plugs would definately NOT recieve power as no connection is there.
So why is the dash light still on.. Is this a warning that something is wrong with the circuit?( I made this fault!)

Prior to wire removal though, complete circuit was intact , but still light ON constant.

3. Is there an (under seat) relay also for the glow circuit?

Plan is to:
1. replace relay (have a spare) - can I check the relay pre-install with multi meter?What to test (ohms etc)
2. replace glow plugs - but I assume from seller that they were not long replaced.

Need to know about the under seat relay circuit (possible issue)
I know my 312D has an underseat relay , once pulled you have NO glow circuit at all (hence no dash light) - you can completely omit the glow setup.(power elimination by pulling relay)

I would expect in these CDi models , everything goes to fault(code issue) , potential limp mode issues.
Could that be my problem? code established , but not deleted.
If so , how can I self-delete codes.

Any help appreciated.

Marty

Hi Marty
This was bound to show up sooner or later as Sprinters get older irrespective of mileage[but I use the term loosely]
Relay may be faulty, glow plug module may be defective,most likely the glow plug has expired as there is a life span on A age and Cycle starts.
Point is which one is defective My Guess No 1
VOLTAGE CAN BE EASILY CHECKED ON A COLD CRANK START WITH ALL CC/S TURNED OFF AS THE VOLTAGE WILL OTHERWISE GIVE YOU A DIFFERENT READING.
Digital volt read out: cold start on a deep cycle 88ah battery mains start.
Turn ignition on, voltage will read from cold 11.3 v this will [progress to 111.5-6v as alternator builds charge.
Glow lights off after two to three seconds from ignition start: Turn key to start;voltage will drop to 10.6-2v, Voltage thunderbolt protection cuts in to build amperage as engine starts and runs at 1000rpm the charge over a 60 second period will build back to 11.8v to 12.4v to full charge 14.2V
If battery is not doing this it's stuffed.
Low voltage will delay your start time especially in cold night conditions as the battery takes longer to build a temperature rating up.
Take your battery to a GOODYEAR OR BATTERY CENTER AND ASK FOR A PRINTOUT ON BATTERY ALT AND PULSE READING.
HOW MANY K'S HAVE YOU YOUR 208 HAS NO ELECTRONIC DASH CODE READOUT SO THIS IS AN EASY FIX.
Richard

RICHARD

Hi mate. Some good info here, I have a similar problem

https://sprinter-source.com/forums/showthread.php?t=6935