I have Owner's Guide; so I will be quoting exactly what they call everything. This truck has a 5A Starter relay fuse located in passenger compartment kick panel and has a 7A Starter fuse in the Power Distribution Box in engine compartment and Starter relay, also in PDB.
Three weeks ago the truck wouldn't start. I discovered that fuse #21, 5A Starter relay fuse blew out. I replaced it and truck worked for three weeks. I tried to start truck this past Monday, and it would not start. I checked fuse #21 and it had blown again. I replaced it and tried to start truck and nothing. I checked fuse again and it had blown once more.
This is where it gets interesting:
- I have a ton of 5A fuses, so I was checking things out and would replace 5A every now and then. Sometimes engine started, but fuse blew out immediately after truck started (you could hear it blow) I would replace it, crank the engine and the fuse would just blow. It did this a couple of times, engine would start and fuse would blow and sometimes no engine start but fuse would blow.
I bridged the fuse with alligator clips and a 40A relay just to see what happens and when testing, sometimes engine would start, but most times it wouldn't. The most times I was able to start it in a row was five. Then it wouldn't start again.
This morning I disconnected wires to starter and removed all wrapping (plastic tubing with rings that has a slit down middle) and they are fine. They were oily, as oil filter is right on top of starter and that area gets a lot of oil when oil is changed.
So as of right now, I am stumped. It seems truck will start with nothing done to it and immediately after turning it off and trying to restart, it won't any more.
When I think about it, logically, it has a 5A Starter relay fuse that blows sometimes and sometimes not. I bridged fuse and truck would start sometimes and sometimes not. I am not sure, but is the job of 5A Starter relay fuse to protect the Starter relay in PDB? Looks like 7A Starter fuse in PDB is not an issue as it is ok and I most likely wasted time checking cables to starter.....
I looked in my haynes manual that goes up to 2005 but could not see any info on the wiring diagram......I think the RAP module is for the fuel pump so it is probably not that.........I also looked on rockauto for you and they did not have a "starter relay" perse......they did have a universal relay.....Have you done any work to it recently?
pawpaw might come around he is good at figuring this stuff out
thanks for looking into it. I think I have the same Haynes you have; the last page of wiring diagrams is for starting/charging.
Only thing I've done is add a flex-a-lite 11/10. All hook-ups are to battery and to A/C wire and it has been working fine.
I don't think my truck has RAP - Looking at starting diagram, chapter 12-29, it goes from ignition, fuse in the middle, options: w/o RAP module and w/ RAP module. If I look at w/ RAP module, it says there's a Starter interrupt relay. I cannot locate a Starter interrupt relay anywhere in my truck or Owner's guide. I doubt all info in Haynes is 100% accurate as they cover 1993 - 2005.
AutoZone has a "universal" starter relay under $10. I may just try that see if it works.
That fuse does not power the starter itself so stop looking in that direction. Component-wise, power flows from that fuse, through a jumper under the dash, through the trans range sensor, then to the starter relay located in the battery junction box. From there it continues on to the PCM, which enables the ground for the circuit for the PATS function.
I would look at the trans range sensor connector first, then inspect the wiring harness for any shorts to ground.
Found short. It was under dash; driver's side. I went to justanswer.com, and selected FORD and was assisted by Ron. I highly recommend Ron who was able to help me with a diagram that is not in Haynes book and was able to lead me while trying to find problem. A lot of communication back and forth for $18.00
This is what he told me to do: "Looking at the diagram ,the starter is the only thing on this circuit. If unplugging the Range sensor dosnt stop it from blowing the problem is in between the fuse and the range sensor, go one step further and locate the clutch pedal jumper under the dash and try disconnecting it and see if it still blows."
This confused me as my truck has an A/T. Ron clarified by saying: "Yes and that why it has the clutch over ride jumper . It would have a switch if it was a standard trans. Take a look at the diagram. It should be near the steering column, the best way to find it is with the white/pink wire where it connects to the pink wire to the range sensor."
So what Ron was referring to is under dash, tucked up high. I tried to take a couple of pictures, but I could not get a good one off.
On this picture you can see the bare section on the wht/pnk wire; far left. I am holding the "dead end" connector, as I call it. (it is capped)
On second picture you can see the whole connector; on the back side it has one of those plastic-push-in-screws; what happened was that it got loose and it was rubbing against parking cable. ( I think factory failed to secure it) I guess over the years it rubbed the insulation off the wht/pnk wire.
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