Location of Glow Plug relay

[356nen]

Hey folks,
This morning my car, an 83 300D Turbo did not start stranding me at home. The bad part is that I had to leave it on the street and will get a ticket because it is permit parking only Well, it would crank but not start. The GP light on the dash was not turning on. It was raining pretty good so I did not get a chance to work on it very long. I assume I should start with the GP relay to bang that around but where is it located??? If I understand (what I read) correctly, if one GP is bad then they will all not work because they are in series?? Well, I need to get this back on the road here soon so I am thinking if I need GP that I would go to the dealer. I am sure they are going to be pricey.
Thanks again.
rene