I have a 2000 f150 4.2Lm The number 5 fuse keeps blowing which controls the AC mode switch, reverse lamps, and cruise. Have replaced fuse with none of the items on and it still blows. I am thinking it a wire grounding out but no clue how to confirm, start to track, or where to go from here. Does anyone have a wiring diagram or know where these wires run so i can track them down? Any help would be great

 

i had the same problem. my fuse kept blowing when i went in reverse but i dont know how it was solved, when my truck went in for a clutch replacement the problem went away

a haynes/chiltons has a wiring diagram in the back

 

Which Fuse panel is the Fuse #5 in ?

When does it blow ? ( as soon as the fuse is installed, when the key is turned on, etc ).

 

Have you gone in for the recall?

 

yes had the cruise recall. the #5 fuse is inside the cab and the fuse will blow within 2 minutes of turning the key to on position. The wiring diagram in the chiltons manual does not show this fuse and is incomplete.

 

Seems to be a Light Blue/Pink wire. Goes to the DTR sensor if auto (or the reversing lamp switch if manual), AC selector switch and temp blend door motor, and the speed control servo.

DTR connection should be on the left side of the transmission, with 11 or so other wires coming out of it. Follow the light blue/pink wire backwards and make sure it's not chafed and grounding somewhere.

The speed control servo connector should be flat, with 8 wires coming from it. Follow the light blue/pink wire back and check for chafing. Also, I'd think you should be able to disconnect this connector and still start the truck, to see if the servo itself is somehow blowing the fuse.

 

Crawl under the truck and inspect the wiring harness that runs to the connector on the transmission. Follow it back and inspect for any point of contact between the harness and either the exhaust or any of the exhaust heat shields.

Fuse F5 circuit on a 2000 is totally unrelated to the SCDS which was the subject of recall 05S28.

 

I continued searching the areas you all recommend, but I had an interesting symtom appear if i put the key in the run position without startin it I left it for more than 5 minutes nothing happen the fuse didn't blow. Then with the only thing I could figure was there had to be an eliment of vibration in the problem which then lead me to under the truck which is what you all told me. When I traced the wires I found they crossed over the transmission and up the fire wall all the while the harness also crossed the exhaust manifold which burned the insulation and with the vibration of the engine would make that wire short out against the manifold.
Any way I first want to thanks everyone for the info. Also hope this final piece help someone else how may have a similar problem.
O by the way call the dealer to just buy a new wiring harness didn't think the cost was out of aline (about $113), but much wiring, vacuum, special water line Ford no longer carries them any more.

 

just repair the harness, no biggie, try and zip tie it out of harms way

 

I am writing this to give my testimony on this subject.
I too had the exact same problem. I was thinking circuit breaker or something. The #5 fuse kept blowing on my 2005 F-150. The shop wanted a lot of money just to troubleshoot. I drove around without cruise control, air conditioning (I live in Houston) until May. I spent a long time searching online until I found this site. I read the problem that ManLikeBear had and it was similar to mine. I read the solution he had to fix his and the suggestion projectSHO89 gave. I want to tell you I went to my transmission and traced it back and found to have a similar problem as ManLike Bear. The wiring harness had either vibrated loosed from its supports or pulled off accidentally by the shop who changes my oil or something and had rested on top of the exhaust and had burned through the wiring cover. Barely even noticeable, unless you knew what you were looking for. I fixed this.. I have a/c and cruise control again.. And I don't have to go down these Houston freeways with my window open listening to the loud 18 wheelers scream by and the tire windings sounds every day. Thank you ManLikeBear and projectSHO89. Next time I drink a beer I will do a toast in you guy's honor. Matt S. Houston

 

I know this is an old thread but I just bought a wrecked SCrew with the same problem. I'm a pseudo shade tree mechanic. I know just enough to get me in trouble. Can someone give me a little more insight on where to find the wire in question? Any info is greatly appreciated.

 

No reverse lights, a/c, or cruise control. (I just bought this truck with 190K miles on it, depending on which odometer I want to use.) There's no voltage at the RD sensor OR at the F5 fuse in the passenger compartment. Should I try to t/s the source of the problem, or can I jumper power to the hot side of the fuse and be done with it?

 

CJB fuse F05 is feed directly off of one of the ignition switch terminals (HOT in RUN/START), RD/BK wire. That same feed also supplies fuse F06 which supplies the shift lock actuator, the instrument cluster and the GEM module. If there are no known anomalies with those items, then it can be assume that the ignition switch feed is good and the problem is an internal open in the fuse box.

If it looks like it's an internal issue then installing a 15A fused jumper from a HOT IN RUN source to the load side of the F05 fuse slot would be a quick and dirty bypass of the (presumed) open. If the fuse holds and everything works, you're done. If it blows, then yo can assume that the PO probably put an oversized fuse in there and managed to let the magic smoke out while never fixing the original problem.

Good luck!

 

Thanks, I will probably try that although I'm not opposed to replacing the cabin fuse box if I can find one at a decent price and the job isn't too difficult. I already had it loose when I was working on my parking brake switch. I don't know how successful I would be trying to remove connectors from the rear of the block, though. Talk about a tight fit.
I'm not too convinced that the ignition switch isn't goobered up, too. Or the GEM, which I don't know much about. I only know that I don't get dash panel test lights, except for the parking brake light.
I'm guessing that there's a single wire going from the ignition switch to the F5/F6 feed.

Anyway, I'm chasing another problem that's probably not related, but I'll mention it here just in case. I'm missing the front left turn signal, same with hazard signals. If the diagram I have is correct the signal originates at the instrument cluster, where I'm guessing it splits off a line to the left/rear park/turn lamp. I can't read the diagram well. I've swapped the bulb with the right side turn signal.
​​​The multifunction switch has been changed and the wiring checked (previously repaired). There seems to be quite a few search results for front left turn signal failures on this vehicle. Is there something I should know? Anything? Just throw me a bone. Maybe there's something about the way these trucks are wired, a pinch-point or wear spot? Is this sounding like an open or shorted wire?
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The more I read about it and think about it the more I wonder if the GEM could be causing problems, whether from a failure or from not being programmed properly. It turns out that the previous owner had changed out the instrument cluster and couldn't start the vehicle. He didn't know that it had to have the parameters reset. So he took it to a dealer and they cut a second key and reset the parameters and retested it. Does resetting the parameters automatically include resetting the GEM, or is it possible that it's not properly programmed now?
According to the PO the 4WD worked before that. With the various functions not working and no power in ACC'Y position I'm wondering about the ignition switch, too.
Without the wiring diagrams idk if the cluster warning lights (which aren't testing) feed through the GEM or the ignition switch or what. Any help or ideas will be greatly appreciated!