Almost finished fixing truck and I have extra pieces...

[Cailen]

So as the title might suggest, I've run in to the problem no backyard mechanic wants to run in to. I have two wiring harnesses and I can only figure out where one goes. I know one of these two blue sensors goes in to the bottom of the air intake ducting.

[BlazerLT]

Cailen, before you do anything, clean your throttle body plate. It looks terribly gunked up with black crud there.

Use TB cleaner and a toothbrush and get both sides of the plate and rinse with the cleaner again.

What other sensor other than the IAT sensor is missing a connection?

[jsgold]

On my 93 there are two plugs that are blue, one to the IAT, the other goes to the TPS sensor. One with three wires - TPS, two wires - IAT. Unsure if there are any more.

[Cailen]

Both those are two wire.. sorry for the bad pic.

The TPS is already connected. Truly I can't find the sensor that is missing a connection; I was hoping you guys could help me out.

[jsgold]

Went and d/c mine. There are three plugs in this general area on mine, the third being underneath the EGR on the engine block. Looks like a temp sensor. all three wires run right through the area you have shown there. If this is not it, advise year and other information as yours might be different...

[Cailen]

I'll go look underneath the EGR, but the EGR sensor is a three wire.

Blazer is a 95 4.3L Vortec Vin W

Here's a better picture:

[jsgold]

No. I said look "under" the EGR valve, on your block. There is a sensor on the engine block, hard to see it, and it is underneath the EGR valve. Looks like it is same connection as your pic. I have a 93 4.3 vin W, the three sensors fed in that area are the TPS, IAC, and a temp sensor. I can't imagine what else this would be...

[BlazerLT]

Cailen, read my last post before you put your intake back on.

Also, check your coolant temperature sensor and you EVAP solenoid for that same connection.