Unused connector/cut wires??

[joep123]

I have a 92 k1500, 350 5.7 tbi and I’ve just rebuilt it from the frame up. While I was tearing it down I noticed that I had 2 wires (black/white & tan) and a connector (pink/black & tan) that didn’t plug into anything. They were laying right by where the coolant temp sensor/thermostat for the intake is at.

I’ve put the truck back together and plugged everything in and don’t see where these wires spills go. The truck ran without them, and is running fine without them now with the new motor installed. It’s not throwing any codes but I’m still wondering what these wires go to.

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[Erik the Awful]

My '89 manual says "Air Switch". Supposedly above the air pump on the right side of the engine, but my truck had a lot of the emissions removed before I got it, so I dunno where it goes.

 

[Schurkey]

Mine still has the AIR pump. I'll look tomorrow.

 

[someotherguy]

'92 doesn't have A.I.R.; it was omitted by then, I think even by '90.

At least 2 of those wires (the black/white, and the tan) are grounds that attach at the thermostat housing or next to it. The number of them vary a small amount over the TBI years but here's an example from a '94:

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(and don't let that little box on the intake in this pic throw you; it's not present prior to '94. it's the evap solenoid, your truck doesn't have it)

Richard

 

[joep123]

Yeah I found a 95 Tahoe at the junkyard with 1 of those and brought it home to put it on. Then I looked at my evap system sticker and it doesn’t have it so I just tossed the thing.

I have 1 set of grounds hooked up by the thermostat housing, I’ll put the other two loose ones on as well.

Is it possible that connector is for the smog pump and they just used the same wire harness for trucks that didn’t have it?

 

[someotherguy]

Yeah I found a 95 Tahoe at the junkyard with 1 of those and brought it home to put it on. Then I looked at my evap system sticker and it doesn’t have it so I just tossed the thing.

I have 1 set of grounds hooked up by the thermostat housing, I’ll put the other two loose ones on as well.

Is it possible that connector is for the smog pump and they just used the same wire harness for trucks that didn’t have it?

It's been years since I worked on one, used to have a '92, and don't recall there being any extra connectors. '94 engine harness does have an extra one sitting on the passenger side intake area but that's a very different harness.

The harnesses change a little bit almost every year but some have more in common than others. Your '92 harness has a lot of differences from the AIR pump era 88-89 harness.

Richard

 

[evilunclegrimace]

I have a '92 in the driveway for a new head gasket. I will have a look and see if it has the plug with the black and pink with black tracer

 

[evilunclegrimace]

My '92 does not have the plug in the OP's pic.

 

[Schurkey]

(pink/black & tan) that didn’t plug into anything. They were laying right by where the coolant temp sensor/thermostat for the intake is at.

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Mine still has the AIR pump. I'll look tomorrow.

OK, "tomorrow" took a few extra days.

I have a BLACK connector, pink/black, and tannish-color wires that plug into my AIR pump diverter solenoid.

 

[PlayingWithTBI]

I have a BLACK connector, pink/black, and tannish-color wires that plug into my AIR pump diverter solenoid.

Mine is black too (88 C1500). It could also be for the EGR - pink/black and brown, or the AIR diverter valve pink/black and gray. Whatever you do, don't ground the pink/black wire at the T-Stat, it's hot with key on!

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Here's my blue EGR connector.

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