1990 5.7L 1500 - codes 32 43 44

[tarabull]

The reason I am looking for a picture of the engine compartment is to make it easier to explain what is missing.

My husband changed the plugs and wires yesterday (engine was stalling/stuttering really badly) and he never touches the cars, it is usually me, buuuuut, I noticed two wires with plug ends that had nothing plugged into them, i will try to explain their location.

1. passenger side firewall, about 3-4 inches away from the dist cap
2. driver side between maybe the 2nd and 3rd plug

now all of the sudden hubby says his temp gauge isn't working at all, and I think that one of these wire has something to do with temp, am I making any sense? Can anyone help me?

[2000CAYukon]

The sensor the temp gauge should be between the #1 and #3 spark plugs on the drivers side. Should be a 1 wire connection and clips onto the sensor.

As far at the wire on passenger side firewall, what color is the wire?

//2000CAYukon

[tarabull]

ok, where is the the sensor for the temp gauge, i know for a fact we are talking about the same wire here... one wire between 1 and 3 is the sensor just a brass color thing sticking out? or is there supposed to be a fitting for the wire to clip onto? I think I am missing a fitting that goes over the brass piece that sticks out cause it doesn't seem like the wire will just clip onto that piece (didn't try it tho, if I had changed the wires/plugs, I would have noticed that I pulled it off)

the second one i want to say is green, it comes out of the bundle of wires that are back on/by the firewall kinda behind the dist. cap

[2000CAYukon]

Originally Posted by tarabull

ok, where is the the sensor for the temp gauge, i know for a fact we are talking about the same wire here... one wire between 1 and 3 is the sensor just a brass color thing sticking out? or is there supposed to be a fitting for the wire to clip onto? I think I am missing a fitting that goes over the brass piece that sticks out cause it doesn't seem like the wire will just clip onto that piece (didn't try it tho, if I had changed the wires/plugs, I would have noticed that I pulled it off)

the second one i want to say is green, it comes out of the bundle of wires that are back on/by the firewall kinda behind the dist. cap

The sensor is screwed into the cylinder head between the 1st two spark plugs (#1 and #3 cylinders).

On my 90 GMC K1500, I don't see a wire coming off the power dist block. However, there is a green connector that goes to the MAP sensor (above the passenger side valve cover). Perhaps this is unplugged.

Otherwise, a picture would probably help.

//2000CAYukon

[tarabull]

I'll snap one tonite and put it up tomorrow, in the mean time I'll check the MAP sensor...
Thanks for your help!

[J-Ri]

Also, sometimes there are wires that don't go anywhere. The very first lower intake I did, I had an extra wire that I couldn't find a place for. We just happened to have another of that vehicle in the lot, so I checked it and there was the same wire, just hanging there.

[tarabull]

all righty then, here are my pictures.
1. What is this plug?
2. Here is the plug against the firewall. - Behind the dipstick
3. Is this what the end of my temp sensor is supposed to look like? Or do I need to replace it?

[2000CAYukon]

Originally Posted by tarabull

all righty then, here are my pictures.
1. What is this plug?
2. Here is the plug against the firewall. - Behind the dipstick
3. Is this what the end of my temp sensor is supposed to look like? Or do I need to replace it?

1 - connects at the back of the AC Compressor. I think it is a high pressure switch but would have to look at the factory manuals to confirm.

2 - Not sure. Will take a look at mine after lunch.

3 - It looks fine. The connector slips over the end of sensor.

//2000CAYukon

[2000CAYukon]

On my 90 (which is a GMC K1500 5.7 700R4), I don't have anything right there; however, it looks like the EST connector that is suppose to be disconnected to set the timing. On mine, this connector is under the black power block cover. When it is disconnected, it sets a code 42 (I think but it could be a 43). The wire color will be black with a brown strip or brown with a black strip (wire color not connector color).

//2000CAYukon

[Dunamis]

Picture 1 - I'm new at this but I looked at my 95 K1500 in the area i which you took the pictures. Although the contact is different on the inside of the plug, because of the plug size, could it be the Coolant Temp Sensor plug, not to be confused with the Coolant Temp Switch(located on the driverside of the engine block)? I took the plug off my compressor and it's different too. Other than those, I have no tother connectors in thatb area.

Picture 2 - Not clue

Picture 3 - I looked up the Coolant Temp Switch for your model truck (2wd) at autozone.com. The plug and connector look different then what's in the picture.


Don't think I helped much, but I tried.