2009 6.4 cluster and radio go on off

batmantech · August 29, 2018

2009 f-450 150,000 miles Has cooler delete and exhaust filter delete. KOEO cluster and radio ok. Start up KOER cluster and radio blank until push accel. pedal down. Then cluster and radio come on. Did network live test ok. Verified the AccDly in datalogger is active when working and inactive when not. Power to radio from accessory delay relay follows concern replaced the relay and replaced the SJB. I now have a code P0102 swapped out sensor same concern checking that now. Truck had other very intermittent concerns of not getting out of park unable to duplicate those. Anyone have experience with anything similar?

batmantech · August 29, 2018

Active commanded rpm with ids, as soon as command 1200 rpm, cluster and radio come on. MAF, radio acm, hvac mod. brake controller mod.all unhooked same concern. reconnect radio unplugged cluster after running command rpm 1200 radio comes on.

batmantech · August 30, 2018

With the help of Ford hotline I was able to fix this concern. Verified that the network was commanding the radio and cluster off during and after cranking. It should only be during cranking. Then checked ignition switch crank circuit, switch operating ok but still had power on circuit. Checked starter relay ok. Found the Otis diode had failed allowing current out on the circuit. So the PCM strategies make this difficult to figure out. If this had been an older truck (where you have to hold the key in crank position) I suspect the starter would have kept cranking even after starting. That would have been much simpler to diag.