1992 300sd w140 glow relay and idle
 

As the title states...

1. car went from easy start on first or second crank to very hard starting only when cold. I replaced the glow plugs, as I knew I had at least one failed. New GP's didn't fix the problem. Very difficult to start cold, but one or two cranks is all it takes when warm. I'm assuming that the Glow relay is bad? All the wires were in good shape. Is there a way to test the Relay before dropping $100 on a new one?

2. I know for most of the OM603's the idle can be somewhat adjusted by the rotary thing, but can someone tell me where this is located on the W140 chassis?

Thanks. As always, the forum has saved me a heap.
Jason

You can use a multimeter to see if the glow relay is energizing the plugs. Replacing the strip fuse regardless of how good it looks is usually a good idea, since they are .50 or so.

They removed the idle adjustment plug on later models.