My 1996 C class Mercedes has a number of unusual random problems which I assume are electrical issues and my mechanic has never seen it before.

Problem 1.
Basically on purely randon occassions the fan will come on full and cannot be turned off.

Problem 2.
The other random problem is all the following things all occur at once, the speedo stops, crusie control won't work and the 3 brake warning lights in the instrument cluster come on all at once and then the car won't idle properly. Then after doing this for a random amount of time everything goes back to normal and the car runs perfectly.

Both these problems occur purely randomly and of course did not occur in front of the mechanic. My mechanic could not find any problems.

I assume I have electrical or computer problems? Does this car have any inbuilt computers???
Help comments or help would be appreciated??