Jump to content

82 720 engine temp wiring


Recommended Posts

Hello. I purchased a 82 720 with the z22 engine in it and I've been slowly going through wiring under the hood. The temperature gauge has never worked and I noticed it looks like the wiring has been disconnected I'm wondering what wire is the one that needs to be connected to the sending unit there are 3 that are yellow with a blue stripe I'm almost positive it's one of these from the research I have done just need clarification thank you.

Link to comment
  • Replies 13
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Look closer. The temperature sender wire is Yellow/Black stripe. It should be near, and reach the sender near the thermostat. Ground this wire and gauge should climb to full HOT. If not the problem is the gauge or the wire to it.

Link to comment

With the ignition on it's power to the fuse to the gauge to the sender to ground. The sender varies the resistance to ground with cold the highest resistance and no reading, to almost no resistance to ground for hot. You can't hurt anything if the wire is grounded, it just reads hot.

Link to comment

Thank you datzenmike. I found 2 wires that are in the same wire harness both are yellow and black and both do exactly as you said they would with the test light on them both also make the gauge move when sent to ground with my power probe. One has a square connector and the other a round connector I would assume one is for the z22 and the other for the z24? I tried to connect the round connector to my sensor and let the truck idle for about 30 min but the gauge never moved? Thoughts ? 

Link to comment

Ok I figured as much. It's strange to me there is also a aftermarket engine temp gauge in the truck that was already in the truck when I got it that is installed just above the thermostat housing and it has never moved either. Yesterday when working on the truck I decided to test the gauge out by boiling some water and putting the sensor in the pot and it worked I re install it in the truck and let it run for a while and no movement from the gauge. I have seen some things on here about engine coolant not getting up to temp does this seem like it could be an issue in my case. Either way I am going to buy a new sender. Thank you.

Link to comment

There wasn't any on the after market one and I haven't pulled the OEM one yet but I will hopefully get to it at some point today also when testing the wires and grounding them out the temp gauge never actually goes above half way is this normal?

Link to comment

I will try that I used my power probe which should send ground directly from the battery ground. The gas gauge works how accurate it is I'm not sure of I have never actually filled the tank up completely with the way gas prices have been🙄.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.