Can anyone tell me what this thing is?? It's broken and I need to get a new one. I can't seem to locate it in any schematics.
Thanks in advance

 

Welcome aboard!

On a GSLSE, that's just a plastic wiring harness mount to control the part that includes the Alternator main (+) connection. It's made out of a fiberglass reinforced plastic and can be roughed up and JB Welded back together. That bolt holding it to the RE-EGI air chamber isn't a ground, as it's bolted into aluminum, but if too tight, it will crack the plastic surrounding it, so be careful.

 

Thank you. I will soak that bolt in penetrating oil for a few days before I attempt to remove it.

 

How stuck is it? Guessing by the corrosion on the bolt head, it looks like you live in wet country (*or the car did...). It's only a harness fastener, so it shouldn't be under a lot of torque. Hit it with the 10mm and you miht be surprised. Again, that's not a ground, so it doesn't require any torque at all - it's just to keep the HOT side of the Alternator wiring up and away from abrasion near potential grounds.

 

Welcome to the forum toneinvic, I have attached a photo of what it looks like "unbroken." When you repair it and reinstall it keep it "centered" between the two protrusions when tightening it, the piece can pivot between them and easily **** it and break your piece again.

 

Why couldn't it be a ground because it bolts to aluminum?

(I mean, yes, it isn't a ground, but still)

 

Two reasons; A) it's holding your (+) power wire and you don't want a ground anywhere near that, and 2) it's attached to aluminum.

 

Aluminum is conductive. The alternator casing is aluminum and ground through its case. The starter body is aluminum and it grounds through its case to the aluminum transmission housing. The rotor housings are aluminum and the spark plugs ground through them.

A lot of vehicles have aluminum wiring, too. Makes the harness a lot lighter and cheaper than copper.

 

Aluminum is not a GOOD conductor. This is why performance gains are easily had by installing a few cheap, copper grounds to important things like alternators and housings and such. Aluminum is used extensively in your list of items because it's light, cheap, and easy to cast. Have a look at this quick table and realize that copper is roughly / almost twice as electrically conductive as aluminum. Iron has poor heat conductivity, which is interesting considering the aluminum housing sandwich in our engines.