on My 83 SD, I got in it this AM, and it would not start. Would not even turn over. The other thing is that wen I turned the key to start, the GP light did not go off.
I also held the key and went through the gears, no catch anywhere.
So I think the ignition switch has an issue? the one behind the key switch.
I jumped the car at the terminals under the hood and it started up fine. then after moving it around the yard, it started by key.

Ignition switch? or NSS? or am I missing something?

Thanks

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83 300SD Dark Silver Dark brown inside

Meaning that the light illuminated and would not extinguish?

Meaning that you jumped the terminals using the vehicle's battery or meaning that you used a second battery?

Yes, I think a key switch issue also. Could be a fluke so I'd just keep driving it until it repeated all the time. My TD typically would fail to energize the starter once every 3 or 4 months for many years and I'd just jump the terminals under the hood. It hasn't done it in over a year now.

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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

Yes, when I turned the key to engage the starter, the GP light stayed on, But would go off at the normal time.
I jumped it, meaning down at the terminal block, to power to starter.

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83 300SD Dark Silver Dark brown inside

Connect a volt meter to the trigger wire on the starter. You should get full battery voltage everytime the key is turned to start.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

There are a fair number of threads on here about those exact symptoms. One member took apart his ignition switch and found some dirty contacts which he cleaned to solve the problem. He put some pictures up of the process. It could also be poor connections elsewhere in the electrical system. I just carry a short piece of romex wire with the ends bared to jump the terminals in the junction box when it happens.

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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

You might check the connections on the starter.

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