Fuse #41 keeps blowing...scan tool says o2 sensor heater circuit malfunction. Problem is that when the o2 sensors are unplugged it keeps blowing fuse the second I hit the key. Any ideas on where this short would be? I can't find a wiring diagram anywhere. ( I'm new to this forum and I'm sure there is a sticky somewhere....can somebody help me?) Dtc codes: p1451, p0743. P0750. P0760. P0765. P1747. P0135. P1409. P0755. P0155

 

Are we supposed to just guess what you're working on?

 

2002 ford ranger 4.0 super cab 4x4

 

Ask in the RANGER forum, you're far more likely to connect with a Ranger owner who's had the same issue than you will here, which is the V6 engine forum. You don't have a V6 issue, you have a Ranger-specific electrical problem.

 

Hi and welcome, I've moved your thread to the Ranger and B-Series forum.

Have you done any work on it lately such as removing/replacing something in the upper end that could have pinched a wire?

 

It looks like that fuse #41 circuit has some other components aside from the 02 sensors, including:

(1) the EVAP emission canister vent valve (which is NOT the EVAP purge valve);

(2) the EGR vacuum regulator solenoid (NOT the DPFE);

(3) the 5R55E transmission.

For starters, what do the 02 sensor wire harnesses look like? Is it possible that a wire harness touched the hot exhaust system and burned through the insulation?

 

Pull the plastic kick panel off on the passenger-side and have a look at the wiring bundle running down the side of the dash and into the fuse block - where it comes out from under the dash, check to see if it's been rubbing against the metal. The bundle is tape-wrapped so, if there is a short, you may have to cut away some of the tape to see it. Also, if there's a short there, you'll probably want to disconnect your battery until it's fixed.

Your symptoms sound very similar to an issue I had a little while back - mine was with a different fuse, but it was a head-scratcher until I stumbled across it by accident - I could see the scorch mark on the metal and there was some sparkin' and smokin' goin' on...

Good luck!