Does anyone know what wires are grounded to the thermostat housing stud on a 4.3 V6? If I remember correctly, it's a tan wire and maybe a black one. The nut that's on top of that stud was rusted on there so tight that the wires broke while I was trying to remove it. At the moment the wires are just hanging loose in the engine compartment, but the truck doesn't seem to be acting up.

Once I got the stud out of the engine and the thermostat changed, I attempted to remove the top nut from the stud by holding the bottom nut with a wrench. That didn't work, my impact gun just spun the whole thing out of the wrench. Locking the lower nut in a vice and repeating the process didn't have any effect either.

I'm not sure if it makes a difference or not, but this particular engine is in a 1989 S-10 pickup, 2WD Automatic.

 

not having grounds is bad mmkay! (only say that because your "the truck doesnt seem to be acting up" comment).

electricity has to go somewhere, and take away the ecm's ability to dump it off to ground and it finds a way through the ecm... dont get me wrong that ground is spliced to another ground (if the schematic is the same as the 99 express van I am familiar with). Redundant systems are redundant for a reason so I like to leave the redundancy when possible... If you have any bolt stores (fastenal or similar) they should be able to get you a stud that you can run your own 2 nuts down on, one to secure the thermostat housing and one for the ground.

 

Hi Red89Dime,

Welcome to the Chevy Forums.

Stoopidnoob is right, grounding is important. You could use pretty much any bolt on the engine that's not frozen as a ground, in order to re-attach these wires.

Also be certain your engine-to-firewall ground strap is clean, as well as your negative cable at the battery.

Many pro mechanics drag their feet about fixing bad cables, because they know corroded wires are going to repeatedly eat through your battery, alternator, and starter, resulting in a lot of repeat business...