Mysterious Plug

drumset5994 · February 1, 2007

I dont have a pic, but i can probably find one.

Ok, working on my truck today gave me some pondering.

My brother has an older 4.3L V6 from a 94 Astro Van in the garage on a mount. On the thermostat housing, there's a little black plastic 2-prong plug, at an angle, a sensor of some sort.

HOWEVER! On my truck, this hole is literally plugged with a large square plug (the back is square).

ALSO! On my truck, there's two connectors bound up with zipties and unused. One connects to the AC Pump (Mine came without AC) ...and there's also a connector for that same sensor that's on the Astrovan's 4.3L.

What exactly is this sensor? Is it something that only AC trucks have?

drumset5994 · February 1, 2007

Here's a catchy little pic i made from Microsoft Paint...somehow i uninstalled Photoshop CS.

Wingnut · February 1, 2007

Could you take a smaller picture of the object? I can still see 4 pixels that you've circled.

And you've discovered the Knuneutson valve diopter adjustment control fuse.

Draenor · February 1, 2007

I just looked on mine, I see the same plug. Its not connected to anything. Maybe it is for an extra or optional accessory? Or maybe it does go to the "Knuneutson valve diopter adjustment control fuse"...Flux capacitor?

HyperBuzzin · February 1, 2007

Could you take a smaller picture of the object? I can still see 4 pixels that you've circled.

And you've discovered the Knuneutson valve diopter adjustment control fuse.

You sure that's not the Knuneutson valve diopter adjustment redirection circuit relay input? (or is it output? I get them two confused)

ZZebes · February 1, 2007

maybe it is a blinker fluid check valve

bobcat5544 · February 1, 2007

The real answer

The conector is for the coolent temp sensor, but it is only used on the astro van with the 4.3L. The plugged hole is were the coolent temp sensor would go if this engine was in the astro van. your coolent temp sensor is on the pass side of the engine.

ZZebes · February 6, 2007

I'm still convinced it is the zerk fitting for the installation of a set of piston return springs

brainpause · February 7, 2007

Nah, it is the muffler bearing joint, but with modified exhaust, this hole gets plugged.

Larry

MrLM7 · February 13, 2007

Brake light belt check port.

bobcat5544 · February 13, 2007

All right I lied it's really the high performance cooter valve hole, for the yogurt shooting piston

1999 Tahoe 4x4 · February 15, 2007

Come on guys. Let's get serious.

It is a valid question.

I wish there was a plug on my truck. I coould use it to help bleeding the cooling system.

redvett · February 15, 2007

If GM didnt use it on your truck its not needed. The harness has to be able to work for different states & countries (export & emissions) dont worry about it.

AirForceAngler · February 23, 2007

Did the Rastro vans have electric fans? If so, that sensor may be for the fans. If not, it may just be the temp sensor and yours is in a different place. You shouldn't need a place to bleed the coolant if the radiator fill is the highest point on the engine. The first (and only so far) car I've seen with coolant bleed points was my wife's Impala.