fuse keeps blowing, CEL on

[TDHunter99]

Hi all, I've been doing alot of reading on here, but ive read all I can read and I still need help. I have a 2001 Ranger edge that I can't keep a fuse in the fuse 41 slot. It blows every time I start the truck. A month or so ago I started the truck on a cold morning, and upon starting it up, the CEL came on and the idle started surging from 1500 rpms to almost stalling. I tracked it down to this fuse being blown, and then I went on to unplug all my o2 sensors checking if it was a bad sensor, and I found that the wires on the one upstream sensor had rubbed through and had exposed the copper wire, which a shorted wire would explain the fuse blowing, right? so I plugged all the sensors back in except that one, cleared my codes, and ordered some new o2 sensors. After that, the CEL came back on, throwing a code for just that single sensor, and the fuse stopped blowing. yesterday my new o2 sensors showed up, I put them on and all seemed normal all day yesterday and this morning, but this evening the CEL came back on and the fuse is blown again, so im stumped at this point. any suggestions on where to begin would be highly appreciated. thanks.

 

[Curious Hound]

Are the wires rubbed through again? If so, you need some way to prevent that. Perhaps zip-tie the wires somewhere so they don't vibrate and rub through the insulation. Or add some tubular woven fiberglass as chafe protection. Maybe the wires are rubbing somewhere else that you haven't found yet.

 

[TDHunter99]

I wrapped the new sensor with plastic tubing and layers of electrical tape, so I dont think its rubbed through again. It is possible that its shorted somewhere else.

 

[adsm08]

I'd start looking at the rest of the wiring.

 

[RonD]

2001 Ranger 4.0l
Fuse 41, 20amp, in engine bay fuse box, powers a few thing

EVAP canister purge valve
EGR vacuum solenoid
Three O2 sensor heaters
And if automatic trans it also powers the solenoids