My 1988 560SEL has an antenna switch on the dash - up is max - middle is normal, bottom is off. When I first got the car, I left the antenna in the middle and when ever the radio was turned on - the antenna would come up half way and stop. If I put it in the max position it would extend all the way up and in either position - when I turn the radio off it went all the way down. I changed the mast with a new one and since then - if the switch is left in the middle position - the antenna will not come up AT ALL - if I put the switch in the top "max" position - when I turn the radio on - the antenna automatically extends all the way. I then put it back in the middle position and when the radio is turned off the antenna goes all the way down whether it is in middle or max position. After the mast was changed - the radio died about 3 months later (stock original Becker unit) Got a rebuilt from Becker and installed it and the same antenna problem exists - so I know it is not the radio. What can cause the ant not to come up half way in the switch middle position - but when the radio is turned off with the ant. switch in the middle position (after extending it in top MAX position) it automatically goes all the way down as it should.
Any ideas - other than a new antenna assembly?