bill1949,
I think this might be a gray area. The '48 wiring diagram shows no relay, but of course this isn't your '49. My first thought would be if your rig HAS the relay, and it appears stock, then it came with it.
I sort of thought this might have been a transitional year for the relay...some had them, some didn't.
I have enclosed a link to a thread on this subject earlier in this forum.
Sorry I can't give you a definite answer, I'll bet someone will though.
http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=3;t=000636#000006
Stuart
