I've been scratching my head why I get the glow plug light sometimes and not other times. This has been happening all summer. Now that it's colder, I been getting hard starts. I checked the glow plugs with an ohmmeter and they all checked ok. I put my non contact ammeter on the battery negative cable and noted sometimes I get full current draw of 5 glow plugs and sometimes I get lower draw of 4 glow plugs. I thought I must have a flakey glow plug that is intermittent, which IMO is very unusual. So I put the non contact ammeter on the individual wires coming off the glow plug relay and found the one that was low current, traced to #1 glow plug. I proceeded to replace that glow plug and guess what? The fricken nut was loose and the ring spade terminal was floating! I tightened the nut, took a non contact ammeter reading to make sure it's drawing full current which it did. Engine starts much better now.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
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