No idea (and I need to know too). I have just bought a heater only unit and need to find the rest of the bits. Ebay seems a good bet and you can buy a manual on there too. That might solve your problem.
Got the manual but cant relate the diagrams to the physical object. Suspect the big one is a control unit and the other is a relay but not sure. Had intended to remove the heater unit to service it but it could be one of the other bits thats kaput.
silver bit is main control box - mine was replaced a few years ago cost c £200 - apparently eber at ringwood will check it for you to see if it is working properly
I rang eberspacher last year about my heater, emailed them some pics a chap called John rang me back went through it with me solved the problem that I had. Wonderful people on that occaision. They may still be as helpfull?
Yes, control box (low current relays and delay timers) and relay (high current for glow plug). The two most common faults are glow plug carboning up (wire brush it) and big (20 amp) fuse melting due to glowplug carboning up. My truck eberspacher suffers from this regularly.
www.espar.com for all the manuals. the silver thing is the control box off one off the old ebers, they have an internal relay that starts to stick, you can fiddle with them BUT to be quite honest they are that old now you may as well bin them and get a newer one of ebay, i get a supply of the D2 airtronics ex BT vans, they work fine, contrary to popular belief, ( the biggest probs with them is the thumble thumbs that fit them and havent got a clue!!)
stu