NJT Wiring and error Codes

[sontours]

I am looking at a 1987 NJT MC-9. I drove it for a bit then it shut down. I was able to restart and then get it back to the shop. Took it to Detroit Diesel they hooked it to pro-link and it showed oil pressure at 0, boost at 14psi. Changed both oil prsssure sensor and boost sensor and checked manual oil pressure gauge all is good but DDEC still shows 0 psi and 14 psi boost. They could not find any code numbers. Not sure why.
I have an 84 MC-9 but obviously notice many other wires and connections in the battery compartment. I am curious if anyone has a wiring diagram for the NJT buses. My MC-9 manuals are for 84 and older.

Has anyone had any similar issues with the DDEC?
This may be opening a can of worms but I thought I would start here.

Thanks,

Phil

1984 MC-9
1998 Renaissance

[stevet903]

Does it drive OK?  Smoke?  Is it DDEC I or DDEC II?

Steve

[sontours]

It drove ok until it lost power then shutdown. I did use the override to get it running. It is a DDEC 1. When I got it going again it would drive for a bit then it would lose power. Sometimes I could get it going again by using the override.
We were most perplexed by the DDEC not seeing oil pressure and also showing boost when running or not. 

The check engine light would go on and off somewhat randomly.
Also on the bottom row of lights to the left of the check engine light, what are the other lights for? I see the trans retarder one but what about the others.

Thanks so much for your help.

Phil

[Len Silva]

I know nothing about DDEC or NJT wiring but generally when you have multiple "weird" things going on, it is a bad ground somewhere.  Much more likely than multiple senders failing at the same time or wiring errors.

[luvrbus]

Does the NJT MCI  have all white wiring like they did on the NJT Eagles