I have a problem that isn't always a problem. Occasionally, and I mean VERY occasionally, my 98 F150 6 cyl. wont start. It seems to happen only when it's hot. I have lights and chimes but no crank. I have replaced the battery, starter and solenoid, and the ignition switch, but it still happens about once every few months. So far all I had to do was let it sit for a while and it starts right up, but it always seems to happen at the worst times (like there's a good time to be stuck)... I guess my next step is the replace the starter relay? Where is it? I can't tell from the posts here if it's in the Power Distribution box under the hood or mounted to the firewall...
Oh and trying it in N doesn't help.
I don't know if it's relevant, but it has a Code Alarms RKE installed.

 

1. The CodeAlarm RKE, is it just an RKE or an alarm.

2. Do you have the factory immobilizer ( the 97-98 had an option, which was included with the parameter alarm that had a key cylinder tamper circuit ) ?

The starter motor relay is mounted on the firewall on the 97-03 MY trucks ( 04+ it was moved to the fuse panel in the cab of the truck ). Not too sure if you were watching the truck info when reviewing threads.

 

The RKE is just an RKE, no alarm. I don't think it has the immobilizer, since there is no indicator on the dash. The RKE has some kind of button on it, but I'm not sure what that does (probably a circuit breaker of some kind). I assume the starter relay is dealer only since I can't seem to find it anywhere

 

Ok, well apparently everyone wants to call it a solenoid switch... found it.

 

Did you check the small wire on the start motor relay, to see if it has power in the start position ?

 

Yes there was power coming from the ignition switch. Since it is starting now, its hard to check for other problems so I just spent the $25.00 and 10 minutes on a new relay, cleaned all the connections and checked all the wires for obvious breaks or bare spots. Now if I can just figure out why the RKE isn't working... I think it may have blown one of the 3 fuses from turning the key so many times on Saturday...

 

The other issue could be the DTR ( Digital Transmission Range ) Sensor.

When you get a no crank no start, is the truck parked level ( i.e. no pressure on the trans ) ?

This is a SWAG, but if the DTR is not in the right place ( contacts slightly out of alignment ) the power from the key will not go to the starter motor relay.

When you get a no crank no start, press and hold the brake, shift into Neutral and try starting it that way.

The DTR only allows voltage to the starter motor relay in park and neutral positions.

The RKE, were you pressing the button on it ?

If so, you could have gone into RKE fob programming mode, which I think Code Alarm does the same thing, once you enter programming mode, it erases all previous RKE fobs.

 

I've tried shifting into Neutral with no success and yes it was parked level. I've even pushed it back a bit and tried in both P and N with no luck...
On the RKE, it quit working at the same time the auto locks quit working, when I was trying to get the truck restarted. Maybe the 3 fuses on the Code Alarm wiring is for the power locks, auto locks, and RKE? Anyway, the power locks work but the auto locks don't and neither does the RKE. I did have to unplug it and move it slightly to get to the ignition switch and I think that erased all the fobs, but that was after they quit working.
Since I can't troubleshoot this until it happens again, I may just replace the DTR since it isn't a terribly expensive part and seems like an easy job.

 

If you good with spending the money, cannot hurt at this point, it is a rounding error cost wise to the other items you have already replaced.

The RKE, loss of power from the truck should not have erased the RKE fobs, they are stored in NVR. Start with checking the fuses, but the button is the programming button, not a circuit breaker.