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PKRWUD · 08-07-2001, 10:53 AM

Good description, tough diagnosis. As far as the switched wire always being hot, the only thing I can think of is a failing switch. Do any other switched circuits have juice when the key is off and the switched MSD wire is hot? If yes, try jiggling the key while someone else watches the MSD wire (with a DMM or a test light) and see if the signal varies. If it does, replace the switch. If it doesn't, check the fuse box where the other affected circuits meet, and you will likely find a melted lead. If no other circuits are hot when the key is off and the MSD wire is hot, then he's got to disconnect only that wire from the harness, and test it again (at the box, not the harness). If it is still hot, there is a short inside the box, and it must be replaced. If it's not, then he must trace that wire into the harness until he finds the source of the voltage.

As far as the no spark condition goes, this may sound stupid, but has he verified that the rotor is still turning with engine rotation? I've seen distributor gears get stripped before from violent intake backfires. If it is working as it should, try attaching a jumper wire securely to the distributor body and to a good, clean ground, other than the engine. Going straight to the battery would be best. Let me know what happens.

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

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08-07-2001, 10:53 AM	#5
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Good description, tough diagnosis. As far as the switched wire always being hot, the only thing I can think of is a failing switch. Do any other switched circuits have juice when the key is off and the switched MSD wire is hot? If yes, try jiggling the key while someone else watches the MSD wire (with a DMM or a test light) and see if the signal varies. If it does, replace the switch. If it doesn't, check the fuse box where the other affected circuits meet, and you will likely find a melted lead. If no other circuits are hot when the key is off and the MSD wire is hot, then he's got to disconnect only that wire from the harness, and test it again (at the box, not the harness). If it is still hot, there is a short inside the box, and it must be replaced. If it's not, then he must trace that wire into the harness until he finds the source of the voltage. As far as the no spark condition goes, this may sound stupid, but has he verified that the rotor is still turning with engine rotation? I've seen distributor gears get stripped before from violent intake backfires. If it is working as it should, try attaching a jumper wire securely to the distributor body and to a good, clean ground, other than the engine. Going straight to the battery would be best. Let me know what happens. Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!