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Hi, I'm new to this forum so apologies if this is in the wrong place or has been covered...and I'm not very techy either lol
I have a 90' Pickup with the 3VZE.
I'm pretty sure the source of my problem is with the O2 sensor since one of the wires on the engine harness side has severed right near the plug. Anyhow, CEL is always on and it is throwing out codes 21,25,26 which is O2 sensor, lean & rich. Gas millage is a little rough.
I presume this wire is the primary culprit? and if so, what's the easiest way going about fixing it? The break is on the engine harness side, not the O2 sensor side, so I can't just fix it with a new sensor. I would hate to have to replace the whole wiring harness...
Generally connectors like that are made with a metal pin or socket that is crimped on to the wire and then pushed into the back of the connector. A small barb holds the pin/socket in place. If you can carefully slide something in around the pin/socket from the mating side (not the side where the wire comes in) you may be able to push the barb down and release the pin/socket so it will slide out of the back of the connector. Then it's just a simple matter of cutting off the damaged wire, stripping a couple of millimeters of insulation from the good end, and soldering it to the pin/socket. Slide it back in until the barb catches and you're good to go.
The toughest part is getting the pin/socket out, but it should be possible with some tinkering with small tools. Connector manufacturers sell tools for removing the connector pins and sockets, but without knowing the manufacturer, it would be hard to find the proper tool.
While soldering might work, you'll notice there are NO soldered connections anywhere on your vehicle. Soldering does not produce a mechanically strong joint, and the temperatures near the O2 sensor could approach the melting point of solder. So attach the terminals like you're supposed to: crimp them. For the pins inside the connector, you need a simple tool like this: http://www.aliexpress.com/item/SN-28...08.3.56.4xCKOM (don't try using a hardware-store tool designed for insulated terminals, and definitely don't try getting away with a pair of pliers)
if you don't have a nearby shop that can do it (not because of skill, but because it's like $80+ for the proper tools and terminal) just get a couple heat shrink butt connectors and a good crimper and bypass that one wire in the connector. if you have to replace it again, it's not all that fun, but it will last till then no problem.
Auto manufacturers use crimping for wiring harnesses primarily because it's faster and cheaper, not necessarily because it's better. Properly done solder joints are actually quite mechanically strong. All of the components on the PC boards in your vehicle, some of them quite large and heavy, are held on by solder, and in the case of surface mount components, there is typically no other mechanical fastening.
Bad solder joints and bad crimps are both worthless, but IMHO it's easier to do a good job of soldering with affordable tools than it is to buy the various high end crimpers necessary to properly crimp all of the different connectors you'll run into. I will guarantee you that, if I solder a connector together in your vehicle, your truck will be in the salvage yard before that connection fails at the solder joint.
In either case, it's important to properly strain relieve the connection. Neither a soldered connection or a crimped connection is inherently adequately strain relieved. Wires are most vulnerable at the point where the copper exits the insulation. The OP's original problem is due to inadequate strain relief on that connection. You need to put heat shrink or tape or a clamp on the wires such that the vibration and pull on the wiring is not focused on that vulnerable spot where the wire exits the insulation and attaches to the connector.
actually, the strain relief is via the seals, and is a lot more forgiving than heatshrink. the op's cause of failure is that the vynil coating became old, stiff, and beaten by road debris. the insulator cracked and the subsiquent wire failure insued. also, i would never solder near the exhaust any amount of current while it's heated can melt the solder.
I'm not sure how close that connector is to the exhaust pipe, but if it's safe for PVC insulation, it's not going to melt solder. I agree that connections where the wire has high temp insulation (like in your toaster) are not good candidates for soldering. That doesn't appear to be the case here.
I also agree that the seal provides the primary local strain relief. However, that wiring harness would likely not have cracked if it was supported properly along its length. Clamps, bundling, protective sheathing, etc., are all important for a reliable harness.
it's inheirently reliably as-is factory. it's obvious physical damage. i've seen the heat shrink actually create the stress-point. if anything, it should have been clipped back in it's mounting hole long ago.
08-27-2015, 01:03 PM
