1986 500 SEC raft of minor problems

[jjrodger]

I have just bought a 1986 500 SEC (series 2) and it has the following niggles with which I urgently need a bit of help. I have done some forum searching but have not got very far.

1. The instrument and console illumination does not work. Given that the fuses are in order and this is a blanket failure, I assume the N40 Instrument Illumination Control Unit has failed? Is this right or could it be something else?

2. The heater is inoperative. The fan works, the air distribution controls work and I even think the a/c works. However, there is no heat coming out at all. I assume this is a broken duo valve. Or could it be something else?

3. The cruise control is inoperative. I assume this is the cruise control amplifier?

4. The driver's side seat memory and fore/aft adjustment does not work. All of the other adjustments work (i.e. up and down and the backrest angle and the headrest). I have not got very far with this. I have squirted cleaner into the switch, but that has not worked. Odd that the memory function doesn't work, too.

5. There is a strange buzzing noise from the passenger side (left on my rhd car). I suspect this may be related to the heater.

Any help is most gratefully appreciated.