As I was working on replacing the fuel pump on my 1971 Dodge Travco motorhome with 413 engine, a wrench sitting on top of the engine, slipped and fell. As fate would have it, it landed, shorting the hot post on the alternator to the block. It sparked for just a second, then did nothing. I removed the battery ground wire and retreived the wrench. Now the ignition switch does not function at all. If I jump the battery hot post from the starter relay to the positive side of the coil, the ignition switch will activate the starter and the engine will run. Remove the jumper wire and everything is dead again.
What happened? Did I fry the alternator and cut the circuit? I've never had a bad alternator cause an ignition switch to die before. Any suggestions? I can't see any burned out fuses and there shouldn't be fuses in that circuitry anyway. There's definitely no current getting to the ignition switch. Anyone had this happen before? Could it be the voltage regulator? Electrical gremlins are the worst.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Check for a burnt fusible link-should be by the starter relay, causing no +12 VDC at the ignition switch(don't think the switch could cause that). Good luck.

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1982 300DT 190K (Diesel Purge + synthetic oil=smoothness at last!!!)
2004 Ford E-350 6.0 L PSD 227K
2006 Dodge Ram 3500 SRW HO Cummins 4X4 48RE 42K (brute force tow vehicle)
2005 Scion xB wife's rolling pop can
1993 GMC Sierra C3500 6.2 142K

Came to a simiilar conclusion. Haven't had a chance to look yet--we got 12 inches of snow today. The other possibility I am considering is whether there's a failure in the ammeter since the line to the ignition goes from starter relay thru that guage (I believe) and it's not reading anything. But that might just be pointing to a bad fusible linkl

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Found the failed fusible link where the wire from the hot post at the starter relay exits the wire harness just behind the ignition switch. Should be similar on most Dodge motorhomes if anyone ever encounters this thread.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13