That relay is not a few hundred dollars - more like $50 to $75 depending on where you buy it. There's a good chance that's the problem. They go bad all the time. The eaisest way to test is to find another 124 and swap them - takes about 5 minutes even if you take a break in the middle of the job. The part number is 201 821 02 47 - fits all 124s I believe. It's located in the relay box right behind the fuse box.