Mystery to me

[blloyd7]

The automobile in question is '87 300 TD.
It has been raining here for a month.
So I load about 250 lb. in the back of the car and am looking forward to seeing how thwe self leveling is functioning.
Start the car, drive a couple of miles, look at the guages and notice that the anti lock light is lit. A minute later I hear/feel and little click and the tack stops functioning and th AC stops putting out cold air.

Check fuses they all appear OK.
Changed 1 I think it was 7.

Park the car.

Next day same story. Same symptoms.

Park the car.

2 or 3 days later no symptoms.

Take it to my tech, he looks at the fuses says I have to leave it. Which I can't do that day.

A week later it rains again, and it all happens again.

Next day no problem. No symptoms.

What on Gods green earth is going on?

Thanks in advance.

Lion