Glow plug light on dash very dim, 1992 300D 2.5 turbo

[fmc99rk]

1992 mercedes 2.5 turbo glow plug light on dash very dim car will not start.

EDIT:
Model: 300D 2.5 turbo
Chassis: W124.128
Years: 1990-1993
Engine: OM602.962 I5

[compress ignite]

If you still have your ORIGINAL Pre-Glow Relay ,There's no 80 Amp fuse,The
Relay is Electronically enabled to "SEE" "Shorts" and disengage.

A Dim bulb indicates a weak battery or a bad (Partial) connection.

Howeveah,

1.With your DMM (Multimeter) [Usually on SALE @ Sears or Harbor Freight]
Measure the Voltage @ the RED (Insulated) single wire at the Glow Relay
[your Glow Relay is mounted on the Driver's Wheel house,front]The RED wire
has BATTERY Voltage (AKA HOT at All Times)

2.Be VERY Diligent in your inspections and find the Pre-Glow Ground wire.
Test it for Continuity.Make sure all it's connections are "Clean,Bright and Tight"

You'll need these instructions (Below) for "Visuals" of what we're talking
about.

http://www.ps2cho.net/downloads/MB%20CD/W124/w124CD1/Program/ETM/ETM.pdf

You'll note the Dash (I.C.) Pre-Glow Light is on the 4 Prong plug for the Relay
(Marked "LA")

All this is just for "Openers" [But,you could always "Get Lucky" and find it above.