Check each of the new once’s through the harness to verify resistance.

I bet you didn’t install one wire correctly, and it’s shifting out.

True story - my 1991 350sd had to have the prechamber pulled, so the GP came out. After all was done, I put the GP back on, wire on (I thought), torqued the nut on (the nut wasn’t captive on this GP wire).

No GP light. Car started fine once, then wouldn’t start as easily the next.

Found a bad GP reading. Turned out that #6 wire was not installed, and touching the block. The relay was self protecting as it was supposed to.

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
2008 ML320 CDI (199k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)