I have heard of GPs testing OK with an ohm meter and still not getting hot. The only real way to know is to remove them and apply 12V through jumper cables or one of those "jumper packs" and see if the tip glows bright orange. Of course, once you go to the trouble of removing them you might as well replace them but it would be interesting to know if your old ones were really working or not. BTW - They should show around .6 ohms to be considered "good" so just getting a reading doesn't mean they are good. What were the actual resistances on each one?

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz