I have just bought my first classic Merc - a 280SLC which has been converted to an OM603 diesel from a W124, its a fine job but there are a few fiddling bits that need sorting, one came to mind last night - a distinct lack of heat! The temp gauge doesn't even flicker yet the rad is fairly hot but there aint a lot getting into the cabin so a couple of questions: Where is the temp sender on an OM603 engine and will it be compatible with the original C107 gauge? How are the heater taps controlled? - I'am guessing they are behind the centre console and most likely to be vacuum - any ideas again? I will be looking at a couple of scrap 107 s tomorrow so might be able to get an idea on how it works before I pull mine apart, of course the other obvious one is the thermostat stuck or not there and I shall have a look at that but it would be reassuring to know if the gauge works first! Thanks in advance and I will be posting a few not too stupid questions I guess but I try to do my share of answering to so your help would be appreciated!