I have no idea how to get into the cluster to see if I can replace the sender and the wire to get the cluster temperature working, so I picked up an aftermarket gauge for a dollar that needs a proper sender to hookup.
OK, here's pictures to help you out. Two pictures of the back of the cluster.
1. See the BIG wing nut in the middle? You need to reach your hand up behind the cluster and unscrew that. That is one of the things that is holding the cluster in.
2. Another thing holding the cluster in is that big cable with the big plug on the end. You need to unplug that.
3. Another thing holding the cluster in is the speedo cable. You need to unscrew that.
4. Another thing holding the cluster in is a rigid oil pressure line. You need to disconnect that probably under the hood where it comes through the firewall. Flare nut wrenches help. There is a rigid tube that connects at the firewall and the other end connects to the cluster where I have 4.
5. Finally there is the temp sender capillary tube. That screws into the engine block and threads to the back of the cluster. It is only removable from the engine block so you need to disconnect it there.
You don't disconnect them necessarily in this order. For instance, you may have to pull the cluster part way out to get to 4 and 3.
What you MUST do carefully is the threading of the capillary tubing through the firewall and to the place where it screws in on the engine. There are probably a couple of clamps holding it in place along the way.
You can swap a good temp gauge with your bad one. For that matter you can repaint all of your needles if you want. I think a decent used temp sender will run you $100+ as this is usually the part of the cluster that doesn't work, usually because someone messes up the capillary tube close to the engine block itself.
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