Yep - check the relay operation too. If you find the relay is toast, you can replace it easily. If you know it needs replacing, you can always experiment with rehabilitating the existing relay. I recently opened mine (the original relay, made in 1983) to discover that 25 years of actuation had left of coating of carbon on the main contacts inside. A bit of careful application of sandpaper, and I was back in business. I'm not saying this is the right plan for everyone, but it did work for me and my situation.

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1984 300D Turbo, 326000 Km, Thistle Green Metallic