The Diesel Stop banner
1 - 6 of 6 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Please help I am lost spent hours tonight trying to help buddy get his 99 f350 7.3 to start. I am lost I dont have 12 volts going to the small stud on the fender solenoid. If I jump 12 volts to that little stud from battery truck starts. But for some reason on that little wire with key on or off I have 5 volts to it I don't understand that but 5 volts must not be enough to open it or it would always be cranking. The truck also has a aftermarket remote start that has been on for years but it will start with remote start no problem. Figured it had to be the starter relay under the column the one with the 15 pin connector on it. So we ran up to advance and got one and figured that would fix it and of course still will not start with key but will start with remote start. I am really confused can you please help us out. Thanks in advance.
 

·
Super Moderator
Joined
·
26,604 Posts
Your buddy's truck has and issue with one of a few things. The 12 V power to the small stud on the fender mounted starter relay comes thru not only the ignition switch, but the DTRS (digital transmission range switch) on the transmission as well (I'm assuming it's an automatic transmission). If it's a manual transmission the Clutch Pedal Position Switch is in the circuit instead. In order for power to get to the starter relay, either the DTRS or CPPS has to be working, and the transmission either in Park or Neutral (or the clutch pedal depressed). The shifter on an automatic can come loose and cause a no-start, so the first step would be to try moving the shifter around while turning the key to start. There are a couple of screws under the column that need to be tightened if the shifter is loose.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
Okay it is a automatic and we also tried to jump between pin 10 and 12 on the DTRS switch and it still would not start. All the linkage in the column and shift cable was all replaced buy ford last year. Everything with the shifter is nice and tight checked all that first and tried to hold past gear and all that with nothing. I would assume the remote start would also need to meet all the standards with the DTRS also. We even tried to jack rear axle up and remote start with it in gear to make sure that wasnt bypassed and nothing only will remote start in park.
 

·
Super Moderator
Joined
·
26,604 Posts
I'm assuming you've checked all the fuses. Using a fuse tester is the best way to do that, as they can sometimes fool the eye.

The ignition switch may have gone bad. There are 4 separate switched circuits in it, and the one for the starter may have gone bad. You should check for 12V starting at the fuses, thru the CPPS jumper block (that replaces the CPPS on an auto truck), DTRS, and the ignition switch. I don't recall which order they're in or the fuse numbers, as I don't have access to my data right now. You should check both input and output of each component with and without the ignition switch in Start position.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #5 ·
I will have him make sure he checked all the fusses again tomorrow but I am pretty sure last night he did pull each fuse and check continuity. He also pulled the ignition switch from under the dash and I had another buddy stop buy and they swapped them from his 01 7.3 and the running truck started right up with his module so his is good.
 

·
Super Moderator
Joined
·
26,604 Posts
OK, here's the skinny on the starting circuit.

From Fuse #20 (50A) under the hood, a light green/violet wire goes to Terminals B4 and B5 on the ignition switch. When the switch is turned to start, power goes to terminal ST on the ignition switch, the output wire is red/lt blue going to the Central Junction Box (fuse/relay panel under the hood) to fuse #20 (15A). From there, the white/pink wire goes to terminal 1 of the CPPS jumper block, and out on terminal 2 dark blue/orange wire to the DTRS terminal 10, then out of the DRTS on terminal 12 on a tan/red wire to the starter solenoid.

Make sure you have power thru the whole circuit thru each component, starting at Fuse #20 output side. When you lose power, back up one component and fix it.
 
1 - 6 of 6 Posts
Top