2002 F150XLT, 4.2 V6, 2wd, 5 speed manual, 96,000 miles

Yesterday afternoon, with no warning, it just doesn't crank. It cranked, started and drove fine until I came out of the grocery store, then no crank. Everything acts normal when I turn it on - the seat belt chime sounds, idiot lights come on momentarily, fuel pump hums, etc., just nothing when I turn the key to the start position - not so much as a click.

I can hook a remote starter to the starter relay, and it cranks, starts and runs normally with the key in the on position. Battery strength seems normal, but it is getting weak since I've been messing with it trying to figure out what's wrong.

I've looked through the fuses in both boxes, and none are blown. I have NOT tested any of the relays in the boxes; I don't know which one it might be, and the list in the owner's manual doesn't label any as being for the start circuit. There is one fuse with "start circuit" in the name; I tested it for continuity and it's good; I tested the blades in its socket and I'm getting 12V out of one.

I bypassed the clutch pedal safety switch - no change. I opened the clutch pedal switch - it's in pristine condition. I tested the switch with a multimeter - the starter circuit closes when the slider goes all the way forward. I had an assistant step on the clutch and try to start it while I put a multimeter on the wire that goes to the starter relay. I got a strange voltage reading (less than 12, I think, but the scale on my multimeter is confusing) when he pressed the clutch down, but there was nothing else when he tried to crank it. These was no reading when he tried to crank it without the clutch pedal pressed.

I'm stumped. What else is there to check? Bad ignition switch? A relay I'm missing? Thanks.

 

Not too sure where you were going with the testing.

Best to check each point in the circuit from a known good ground.

Check for + VDC when in the start position at :

1. White w/ pink stripe wire at the clutch pedal position switch
if + VDC
2. at the Dark Blue w/ orange stripe wire at the clutch pedal position switch.
if + VDC
3. at the tan w/ red stripe wire at the starter motor relay on the firewall.

If you can hook a remote starter switch to the starter motor relay and it will start, I am expecting one of these not to test good.






2001 EVTM 20-1 Start system