Did you ever figure this out? I'm having the same issue. The R52 looks exactly like the part I pulled from my R57 and it's half the price.

 

Yes, it’s the same connector and fitting underneath but it’s slightly shorter at each end. I replaced mine with one and it works and it doesn’t seem to have let water in after the horrible rain we have had in the U.K. but you can tell when looking at it that it’s not the exact same as the R57 one. I’m still going to keep an eye out for an R57 one but not while they are at that price.