ok folks, i have an '05 international bus with a DT466 and it eats power relays like they are candy, when i scan it the IDM power relay has "low voltage" but actually has "no voltage"!! pop in a new relay and starts right away and it will last anywhere from 2 weeks to 2 months but not much longer. shouldnt there be a fuse in the battery box that could offer some protection to the relay, i am pouring over schematics trying to find a weak leak in the armor.
check your clean power harness right by the frame rail near the starter had many issues in that area found many Green terminals on that plug seems when ya wiggle it changing the relay it works again for a short time
How did you get the gosinta in the whatchamacallit
I am very familiar with this problem. First off i have have found a good fix. I find the IDM replay on the firewall will melt or burn the pigtail as well as the relay. The 2 ignition relays in the side panel are also prone to burning.
IF you haven't, start with the clean power harness. it runs from the batteries to a connector by the starter. Also if you are so implyed the fuse holder can be replaced with 3 Maxi fuses for more longevity.
Next i bought relay bases from International. Every time i have the firewall relay go bad i also replace the relay base because it melts.
As for the side panel ignition relays if you can find a 50 amp relay to replace it they will last a few weeks longer.
My personal opinion is that the IDM is a bad design on the 2005 model. It was the first year for the new body and engine. So the IDM needs 39 amps and the fuse and circuit are only 40. now that they are old the resistance has gone up in the IDM, injectors, and injector harness so the IDM pulled extra power and overheats the circuit. If you go through everything else and have the extra budget you can try to replace the IDM. International has told me there is nothing wrong with it so my district would rather keep putting in cheap relays then a pricey comfuser.
I had a bus that would go out on a run and die . IDM had no power or low power .Install a new relay and start right up . Next day same thing . Turned out it was dirty power . Ran a complete new wire problem went away .Then the ECM wire did the same thing and fixed it the same way