Hello. need some serious help. My 02 F-150 4x4 5.4 died. Long short, went to U-Haul to rent a car transporter. Hitched it up and when we plugged in the lights got nothing on the trailer. Strange, always worked before. Checked power out of factory hitch plug, notta. checked fuses, found a couple under the hood cooked. Replaced them and heard a loud CLICK from inside. When i tried to start it all the gauges maxed out and nothing. CLICK CLICK CLICK dead battery??? We jumped it and got it to run but barely, sounds like it's running on 5cyls. Had to have it towed home and can get it to start but still no power and when you rev it up it starts to miss. It'a ll it can do to move a few feet on a level surface. All the while the OD light on the shifter is blinking. Checked all fuses and all are fine. WTF????!!!

 

I have no information on 02 F150s, but another moderator with the screename SSCULLY might be able to give you some thoughts. It might be important to know which fuses you had to replace. Can you provide that information?

What you're describing sounds a bit like the "limp home mode", but I don't know if your truck has that feature. Is the check engine light on?

Do you have a voltmeter? If you check the battery voltage with the truck off, is it above 12.4 V? If not, you probably DO have a bad (or at least low charged) battery, but why it would give you the other symptoms is beyond me.

If you can answer these questions, SSCULLY will have a more complete picture.

- Jack

 

After checking the battery voltage and the battery connections at both ends, one fuse to check is CJB ( aka Central Junction Box or cab fuse panel ) Fuse #30, 30A. This is only hot in the start or run positions, so you need to turn the key to the run position before checking both sides with a meter ( don't reply on the visual inspection method ).

This powers the PCM Power relay, which feeds quite a bit in the engine controls.

Next is to check BJB ( battery Junction Box / engine compartment fuse panel ) fuse #2, 30A. This feeds the PCM power relay normally open contacts, for powering BJB fuses #23 & 18.

BJB Fuse 23 feeds the upstream and downstream O2 sensors. If you have chaffing wires to / from either O2 sensor pairs, this can cause a blown fuse.

BJB Fuse #23 also feeds the Transmission controls, which include the shift solenoids. If BJB Fuse #23 is dead, this could lead to the error reporting ( blinking OD light ) by the PCM ( trans controls are monitored by the PCM ).

If you have chaffed O2 sensor wires ( need to check up under the heat shields as well, they can be hard to find ) this could be the cause of a blown fuse, and the reporting by the PCM.

You will need to crawl under the truck, and check from the O2 sensor, up into the engine compartment. This will be quite a pain on the passenger side, but be very mindful of checking the wiring under the heat shields. I have seen this as the chaffing point ( buried under the heat shield ).

This is in tandem to Jack's recommendation of checking the battery.

Also might want to check for voltage on both sides of the fuse links, and BJB Fuse #11 20A ( again with a meter ), Fuse #11 is the regulator field fuse.

Not sure why you had this happen when hooking up to the trailer, I am guessing the trailer has been changed to work with someone's broken truck. This makes for fun, in terms of checking every fuse with a meter.

If you cannot find an O2 sensor harness problem, next is to pull the connectors on the trans, and check the connectors for corrosion or damage, but start with the fuses listed above checking with a meter, and let us know what happens.

 

OK thanks, i'll start checking those things out tomorrow. Odd though that it all started when plugging in a trailer light harness. Maybe just a HUGE coinscidence but ran great up until that point and then instant death.

 

OK somebody please explain. After my tramatic time at U-Haul and the towing and all that $$$....last night put the charger on the disconected battery and let it sit overnight. This mornign the "green eye" in the battery was no longer visable, just black. Ok so figuring that even if it wasn't the problem it was the OE battery and after 7-1/2 years it had served me very well and was ready for replacement. So after a trip to Sears to get a new DieHard, we checked all fuses with a tester and all looked good so hooked up the battery and VAROOM!!!! started like it was new. gave it a good stomp and it didn't die, just wanted to go BUT the PCV vale was making what i would call a death rattle, thought i had burnt an injector or a coil but no, it was the PCV valve??? I'll need to replace that tomorrow but :WTF: why would a dead battery cause all this havoc??? I'll say that maybe the hitch light fuses just went cause maybe water got in it and they did what they were suposed to do but why would a dead battery cripple my truck?? Just looking for some answers. Why why why

 

I would say due to the fact everything is electronically controlled would be a good answer.

I can't guess as to why the battery took a powder, but when you charged it, did you check the voltage on it, after sitting after a charge ?