The Diesel Stop banner

Starting Problems

924 Views 5 Replies 2 Participants Last post by  poolguy2
99 F250 7.3. I went to start the truck and when the key got to the "on" position the starter engaged. I hadnt turned the key to the start position yet. The truck will start but the starter stays on. I've checked several things and noticed that the curcuit that engages the starter runs from the ignition switch to the transmission positon switch and then to the starter relay. If the position switch went haywire would it keep the circuit closed?
Because if I put the truck in gear it wont start, only in park.

I've already replaced the ignition switch and starter relay, any ideas?
1 - 2 of 6 Posts
The DTR is not the problem, it only routes circuits. If the starter engages in "ON", but only in park and neutral, the problem is the ignition switch. Yours has some internal issues that is applying power to the start terminals before it should.
Perhaps a crossed wire in the DTR. Looking at the schematics, power is applied to the start circuit at the ign sw. It then goes to the CPP jumper, then to the DTR on pin10 DB/O wire. If the selector is in P or N, that connects pin 10 to pin 12 (T/R), which then goes to the starter relay on the fender. You should be able to get a voltage reading on the DTR wires with no problems. Unplug the DTR and see if there's 12vdc on pin 10 (DB/O) with the ign ON. There should only be power there when in START.
1 - 2 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.