Electrical Temperature Guage Not Working

[Virtual]

I've been pretty silent on here, but that's good news.. It's mainly just that everything has been running and working great. Until now Forgive the stooopid question, but I'm hoping someone can help me troubleshoot my temperature gauge issue. My Chiltern and Hayes manuals are pretty useless about this, or I'm pretty useless and don't know what to look up in them

Just recently my temp gauge on the dash stopped working. It just bottoms out and shows no temp. I messed around behind the dash a little and have convinced myself it's not the gauge itself, since I can get it to move. So it's either the sending unit or something along the pathway to the dash. I'm not even sure where the temperature sending unit is? Anyone have a picture of where it is located? Once I find that, I'm hoping it's pretty straightforward to check it's operation and then (assuming it's working) trace the circuit back to the dash. basically I need to get started though, so any pointers and procedures would be appreciated. Thanks,

 

[mikestang63]

most liklely it's the sending unit, which is installed in the lower intake manifold in the driver front area. You will see a wire coming off of it.. To test the sending unit. remove the wire off the sending unit and ground it , then turn the key on for a second or two and then back off. You should see the temperature gauge move. If not, most likely the sending unit is bad. Easy fix and a $10 part. If the gauge doesnt move, then check all the grounds in the engine- the strap off the back of the engine to the firewall, the ground behind the battery, and also the actual sending unit wire to see if it is damaged.

It's the brass fitting screwed into the intake right behind the distributor. When you install the new one, do not use a lot of teflon tape as that will interfere with the unit being grounded and will throw off the reading. They normally come with a teflon paste or compound on the threads.

 

[Virtual]

I wish all issues were this easy to solve. Isolated the problem to the sending unit and ordered a new one.

Replacement was an easy 10 min fix, with time in there to partially drain the radiator, which seemed like the right thing to do, even though the sender seems pretty high in the system. My only snafu was was that my radiator drain plug somehow turned into the Kennedy bullet, when it slipped out of my hands somehow went around the radiator, up and to the left, and ended up nestled in my front bumper cover. I, of course, didn't know this at the time since I couldn't find it and couldn't figure out where it went

Ended up letting the radiator drain completely (since I had nothing to plug it with anymore) and used it as an excuse for a radiator flush. Once it stopped draining I was eventually able to find the plug, did the flush, replaced the coolant and confirmed everything was hunky-dory. Cost me more for the anti-freeze than it did for the temperature sender.

@mikestang63. Thanks for the assistance.

 

[mikestang63]

great. Glad that ended up being the problem.