Have my ignition lock and switch out, finally

[junqueyardjim]

A warm humid morning, but I got the whole ignition assembly out of the parts car. There is no reason to suspect this one not to be working. BUT, can anybody tell me how I can test this one. I thought by seperating the lock from the ignition I might be able to see something, but no can do. Also, on the one that has failed, how could I know if it is the mechanical lock section or the ignition section that failed. Remember, 85 W123 Diesel will not crank, but cranks when jumped at the 3 screw terminal box by the battery. Would it be logical to assume that the failure is in the ignition section?

[junqueyardjim]

Any ideas as to where to go from here guys. I switched the unit with the parts car. Parts are dated, original was built in 84, the one in the parts car did look factory fresh - brand new, and carries the date in two places 1996. So I hung it from the connector at the end of the wire loom, hooked up the battery, did a quick check of cranking at the terminal block which checked OK. Went and tried it on the ignition switch, nothing. Where do you think I should look next"? I really need this car and any help would be appreciated.

[Habanero]

Have you checked wire continuity? Perhaps a wire in the ignition loom is broken.

[Mike123]

I agree that wire continuity warrants checking. Also, have you checked the neutral safety switch? A problem in either or those areas could cause the problem you are having.

By the way, I live in Noblesville. I believe you are the member closest to me now.

[Mike123]

Do you have an electrical schematic? You can download that from http://skinnerbox.steaky.org/Service/W123/w123CD2/Program/ETM/83_300.pdf. If you can't I could email it to you or fax it to you.

[junqueyardjim]

Mike, I didn't know we had a forumn member in Noblesville. Give me a call on 984 2860 so we can talk. Yes it looks now like a wiring problem. I worked so hard get the unit out of my car this morning. It had be in there for 20 plus years and it was so tight. But when I plugged in the new one, (from the parts car but looks like it was just installed) same old story. It is too hot for me out there this afternoon, and I have to work in the Pork Tent at the State Fair tomorrow. My friend Ned Kimbrell, also a bus driver and a good mechanic is going to stop over early Thursday to see if we can figure this out. According to early threads in the DIY pages if the back up lites work, the neutral safety switch is not the problem. But we will check that again