Temperature Gauge at Max and Light is On

[Highwayman68]

I tried to search for a thread on this but that didn't go well.

Suddenly the Temperature gauge is maxed out and the warning light is lite on my 68. I know this is a common issue but I can't remember what it is I am to be looking for. The engine has been off for several hours and is cold but the gauge and the light are still indicating over temperature.

[TJ Hopland]

IF this was a few years newer I would have some guesses as to how both of those could be related but I don't think any of that applies to a 67.   I will be curious to hear what it turns out to be.

["Cadillac Kid" Greg Surfas 15364]

If both the "engine temperature" light (and buzzer) and the temperature gage both indicate "Hot" with the engine cold, it would suggest you have an electrical ground someplace in the wiring. The "engine temperature" light is activated by the sensor at the rear of the driver's side cylinder head, so you might start there and check that
Greg Surfas

[The Tassie Devil(le)]

When did Cadillac start to use the Engine Temperature buzzer?

Bruce.

[Jeff Rosansky CLC #28373]

Disconnect both sensors and see if you still have the issue. If so, then it is wiring.
Unfortunately I would think wiring because they are 2 separate sensors.
Jeff R

[cadillacmike68]

IF this was a few years newer I would have some guesses as to how both of those could be related but I don't think any of that applies to a 67.   I will be curious to hear what it turns out to be.

Mark has a 1968 and that was the first year of the buzzer.

It could be a bad ground. of the buzzer sensor is bad (or internally shorted??).

Mark - your engine's back in?? Great.

[The Tassie Devil(le)]

Ah ha.   Did someone switch the sensors around?

When the AC sensor is put in the Stop Engine Temperature spot, it doesn't take long for that one to blast away the warning buzzer.

Plus, it takes a long time for the engine to cool down to turn that one off.

I know from experience.

Bruce.

[Highwayman68]

Yeah the engine is in but not timed or tuned yet. I had to leave for a short trip to Pittsburgh. I will get back on this around July 5th.

The sensor is open in normal temperature but once it is installed and I connect the wire the light comes on. BTW I disconnected the buzzer back around 1981 so not sure if it even works now.