My Bav's only had the high beam relay, but they were a 69 and 71 so may be different from yours. The original relays were round and relatively large, but can be replaced by the later small square ones, they plug in just fine, the prongs are the same and in the same place, the body is just smaller. One possible complication, on the 320's I know they used a different relay for the low beam, it had a normally closed contact along with the normally open one. I don't know if your car would have that also. They used the small square relays at least until the late 80's (that is as new as I have messed with) and I am sure they are still available. If the horn works, try using that relay, it is the same. Mike