I am working on my parents 99 Bravada 4.3L V6.

When driving, it would lose power and try to stall at low speed or at a stop. I noticed that the dash temp gauge would drop when this would happen (not all the time but most of the time). This led me to the temperature sensor. Now from my understanding, there is only 1 sensor for these engines on the drivers side of the engine in the block. It has 2 wires so I’m assuming one of them is for the dash and one is for the computer and the ground comes from it being in contact with the head. I ordered an AC Delco replacement and changed it out this weekend. The connector is on it and it is not loose. I say this because it no longer works at all. No fluctuations or anything. But the good news is that now it doesn’t do the drop in power. My question is, if I am right about the dash and the computer coming from different leads is it possible that the sensor is bad and is only working on 1 lead? Or could the connector be bad as well?

Where on the gauge is the truck running at normally, and where does it drop to when issues develop?

It never got above the middle but would drop anywhere between low to the middle when it would lose power.

Follow both wires, check for places where the insulation has rubbed through or any other defects.

I was finally able to change the wire today. (snuck out of work for a few minutes before it start raining) and temporarily connected the new pigtail to the original wiring. The pigtail came with about a ft or so of wire but i just snipped off the old plug along with a few inches of the old wires and just twisted the wires together. I forgot my crimpers so thats why I am just twisting them for now. I will probably cut back further on the old wires and properly put a weather proof butt-connector on them when I find my crimpers. I let it run for a few minutes and the temp gauge was moving so I'll take that as a good sign. I will know more once I can get some road under the tires.

Drove it all weekend and the temp never dropped and it never shuttered as bad as it did before. I do believe it was the pigtail on the sensor the whole time but hey, now I have a new sensor as well. On to the next problem.

Thanks for letting us know how it went!