Did it need new ones?
You're best arming yourself with a cheap multimeter and then you can check to see if any have gone open circuit or whether they are getting power in the first place. Replacing things before making a diagnosis can get expensive!
Anyone out there in diy world
Is it producing a 12V output for an appropriate period? Telling us it "looks fine" isn't a great deal of help.
Nope, but I've crossposted this to uk.rec.cars.maintenace where you'll stand a better chance of getting a reply from someone much better informed than me! ;-)
Tim