question about glow plug indicator
 

hey guys im still a noob to this entire world of mercedes and diesel. my question is i know you have to turn the key to position 2 to let the glow plugs warm up before you start the motor. wait till the yellow indicator light goes off then its safe to start. my problem is my indicator lite in the dash comes on and then goes immediatly off. i wait till the battery buzz stops and then count to eight and it seems to crank up fine.....any help would be great on why the light would just come on and then go immediatly off???? Help me please i really like my 300sd and look forward to having it and restoring it for many years....i dont wanna do anything to hurt her

The Glow Plug Light is connected to a temp sensor inside of the Glow Plug Relay and give and indication of how long to to keep your Glow Plugs on. However, The Glow Plug timer is actually independant of the Light. If you keep the Key in the PreGlow position long enough you may hear you Relay click off.

Another use for the Gloe Plug Indicator Light is if you have a problem with some of your Glow Plugs it will act funny.
Go to the Diesel Giant (spelling?) and he has a Pictoral on how to test your Glow Plugs with a Volt/Ohm Meter. (This is not a recommendation to buy parts from him.)

So either it is warm where you are and your Glow Plug Light is turning off fast becaust the temp sensor is telling it to turn off or you have a problem with 1 or more Glow Plugs.

Also, pull the plastic cover off of the Glow Plug Relay and you will see it has a Metal Strip Fuse (80 amp). You might consider buying an extra one (Winter is coming). I have never burned on but mine developed a Crack and I have read of others haveing them crack also.

Does this occur when the car has already been driven, engine all ready warm, or is this happening when the engine is cold, say first time you start the car in the morning? If the engine is already warmed up then the light will go off very shortly after turning the key to position #2.

ok it is really warm where i live...i live in south, ga. but this is occuring all the time. first thing in the morning when im starting the car to go to work, after driving it around town doing errands and everything. Diesel9122 ill go to that site and see if i can get that done and also check on those realys. i apperciate all the help guys. the parts store here in town is trying to help me locate a chilton manual for the car so i can start getting a better knowledge of whats going on under the hood...ill keep you guys updated on what i find out...thanks again for all your help

Don't buy the Chilton's or Hayne's manual. The factory service manual on DVD is cheaper.

Chances are, your glow plugs are as old as your car, mine were. Decided to change them due to intermittent indications. Not bad after 28 years. The Bosch plugs are CDN$9.00 each. Do follow Diesel9112's advice. Test the plugs to make sure they're all good before installing as recommended in the DieselGiant.com. Only takes less than 4 seconds to start. After normal operating temp. and shutdown it only takes 2 seconds to start up.

Cycleboy, where is the best place to get the DVD, I cannot find a refernce anywhere through google?

Thanks

Barrowboy

Get it from the Mercedes Classics Center

http://www.mbusa.com/mercedes/#/only...classicCenter/