All;

In addition to the relay mounted in the engine compartment, is there a secondary relay located behind the dash that controls the pre-heat indicator light mounted on the dash?

Past several colder mornings (40 degrees, but hey, it's Virginia) shortly after startup, I would hear what sounded like a relay chattering or an electrical short coming from behind the center console in my '85 300TD. After just a minute or two it would quiet, and then no re-occurence until the following morning.

Attempted to remove the center console this past Sunday, but the Haynes manual led me astray (or I failed to pull hard enough). I was able to remove all switches, heater control assy, radio, etc. so I could see back in there. It didn't appear that there were any relays back there, though there are four small metal cans approximately 1 cm. on a side back behind the heater assy. Started the car, no out of the ordinary noises (but it was warm that afternoon)

Now the glow-plug dash indicator fails to come on when the key is placed in the II position, but the glow plugs appear to be pre-heating because the car is quickly starting. Hasn't gotten back into the 40's, and I've not heard the sounds since Monday when I noticed the pre-heat light is no longer on upon start-up (it did chatter/buzz first thing that morning however).

Just coincidence, and the dash indicator bulb has burned out, or is something else going on?

... and speaking of bulbs, are Osram 2721's the right fit for all the bulbs used for center cosole illumination? I'd read stories that some bulbs are to be avoided; too hot, and prone to melting holders, etc. Is it also a 2721 in the glow-plug heater indicator on the dash (I want to have what I need on hand before I tear into the instrument cluster).

Thanks in advance