Looks like this is the glow plug relay you've been looking for; it's only at $2.25 right now but it is a $120 part new... if you didn't have an immediate need for one, I'd be tempted to get one as backup at that price. In case I was stranded with just a toolkit and a used glow plug relay, I could put it in myself if I had to. (Never did one, but given a lot of time, good lighting and adequate tools, how hard can it be to change one relay?)

__________________
Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
2007 Honda Odyssey Touring, 2014 E350 4matic