the guys just put a new trans in this bus they started up ran good test drove it to make sure everything was good now this morning it would not start i had engine light on and the warn engine displayed under the mileage it cranked over but no start i checked to see if there was power at the idm fuse on the firewall and there was not so i powered it up cranked engine and it started my question is where does that fuse get its key on power from i got no wiring diagrams this is a pre dpf bus it does have egr but no dpf stuff o and it a ce300
Edited by - dsalinas1939 on 07/10/2019 05:13:44 AM
ok so fuse f7 on the firewall forthe idm relay the purple lead gose the the ecmfuse in battery box because its key on power and the fuses in battery box are constent power?
ok i have power at my idm relay i have ground when key is on the relay doesnt cliclk on so i swapped and still nothing no poer at the idm fuse f7 on firewll so i powered up that fuse so i could move the bus because its in the way and now it wont start it did when i powered it up this morning uggggg but i am gonna assume that the fuse goes right to idm???????
Donot get confused, IDM fuse is NOT on firewall, it's on the top of battery inside battery box, IDM relay is on firewall. you need to understand how the circuit works, power came from battery passed fuse to IDM relay pin 30, if driver turn ignition on, pin 85 and 86 inside relay active pin 30 and 87, IDM get power.
what was throwin me off is that fuse f7 on firewall which says one the plate with fuse diagram would have 12v sometimes and when i powered up the idm relay the bus ran so it was losing key would so i drove my self nuts for a while then i thought about it and what was happing was it was losing the 12v all the time power when cranking so i checked the connector and fuses in batter box they where good then i looked by the started and there was the three pin connector that when i opened it it was corroded so it had volts only until i v=cranked it and it had a volts drop not allow idm to work but i got it finally thanks for help guys