IDM question

bbjordan

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My brother picked up a 1997 Thomas International 3800 School bus with a T444E in it. He bought it not running and is now trying to get it running. It will crank by jumpering the solenoid on the starter, but will not run. Does anyone know if the IDM on this is interchangable with the PowerStroke IDM?

I'm thinking not, because I swapped it with the IDM in my 1997 F-250. Neither vehicle ran. I realize this test is not conclusive. But I do know that the Navistar IDM # 1807248C3 did not work in my F-250. It could be a bad IDM, but I suspect the no crank/start condition in the bus is due to some safety lock-out circuit. We're currently trying to track down a wiring diagram for this beast.

This bus was used in the Oilsands and the underside of the bus is caked in mud. The starter had to be chipped out of the dried mud to replace it. :p
 

bbjordan

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After doing some homework examining pinouts of the IDMs, it looks like the pins are not the same. For example pin 3 is not used on the Ford IDM, but the Navistar IDM uses it for the Fuel Delivery Command Signal Input. Pin 17 on the Ford IDM is used for that.

Ah, 20 year old wiring...what fun.
 

79jasper

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I looked and wasn't able to find diagrams. Many people said try international, but said they likely wouldn't have them for anything older than 2002.

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Dieselcrawler

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Check all the fuses and connections in the battery box and the three wire bundle that heads to the starter. do the glow plugs cycle and injectors click when key on?
 

Dieselcrawler

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also nothing electronic wise will interchange from ford 7.3 to international 7.3. IDM and ECM are VERY different.
 

bbjordan

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When the key on, there is a click under the dash, the gauges do a sweep, and the engine and WTS light comes on. I've never noticed the injectors click.
 

Dieselcrawler

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Ok so if the glow plug light comes on, the ecm is getting power. Once it gets light out I will wander out to our one lonely 7.3 powered bus and snap some pics of stuff to check.
 

bbjordan

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Ok, brother managed to pull some code from the bus:

223/622//124/135/222/224/335/223/622/615///

The "/"s is the Oil/Water light flashing.

active codes 223, 622

From the fine manual:

223 - DCUATA - VPM not communicating with ECM
622 - VPM - Engine using Field Default rating

Hmm, VPM problem?
 

Dieselcrawler

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well it sounds like they may of fried something on it, hopefully it wasn't you when you switched the IDM out with yours...
 
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Dieselcrawler

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Lol, yea you got me on this one. Without hooking a laptop to it I can't tell you where to look
 

bbjordan

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Update 1.

My brother got the bus running. After connecting a lanner device

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tapping into the wires, reverse engineering the code etc. and finding it wasn't gettting FDCS...it turned out to be fuse #2 under the dash was not seated properly.

Sigh. I told him to check the fuses, which he did. Fuse was ok, but if it isn't in the right place...guess what? it doesn't work. Oh well, he sure learned a lot!
 
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