I have a 1998 E300TD with 122,000 miles on it. I started having a problem with the horn, garage door opener and sometimes the auto door locks. The horn and garage door opener work when the key is in pos. 2 but when the car is started the horn and garage door opener do not work. The garage door opener is not an issue but the horn is a safety feature and needed to pass inspection. All the fuses check out (engine, drivers side door and under back seat). Is there something in the computer that would tell the horn not to work when the car is started? I disconnected the battery for about 20 minutes and it does the same thing. I know it was disconnected long enough because the BAS code came up which was caused by the voltage drop.

I know there is something probably simple that I have missed but with the vast experience and brain power of this forum I know someone has had this experience before.

Any help would be greatly appreciated. Oh and one other thing is that when the car is first started and is driven in about 200 yards there is a hesitation like a vacuum switch or something then the car drives perfect.