72 Temperature Gauge Issues
Thread Starter
Instructor
Joined: Dec 2016
Posts: 218
Likes: 42
From: Hopedale Mass
72 Temperature Gauge Issues
Before I start ripping things apart can someone tell me how the temperature gauge in my 72 should read when working properly? It has never worked for me so I have no clue. As of now the needle just stays between 150 and 200 and never moves.
1. When the car is off where should the needle rest?
2. As soon as I start the car should I see any immediate movement at all?
1. When the car is off where should the needle rest?
2. As soon as I start the car should I see any immediate movement at all?
Team Owner
Joined: Sep 2006
Posts: 31,285
Likes: 4,374
From: Westminster Maryland
Hi m,
With the ignition off the temperature gauge needle should be to the left side of the gauge (on the 100 numerals).
When turning the ignition on the needle should IMMEDIATELY move to the right to the long line indicating the beginning of the temperature scale.
Have you checked to see if the connection to the temperature sender in the left side head is there?
Regards,
Alan
Ignition on, cold engine.
With the ignition off the temperature gauge needle should be to the left side of the gauge (on the 100 numerals).
When turning the ignition on the needle should IMMEDIATELY move to the right to the long line indicating the beginning of the temperature scale.
Have you checked to see if the connection to the temperature sender in the left side head is there?
Regards,
Alan
Ignition on, cold engine.
Last edited by Alan 71; Oct 2, 2017 at 02:30 PM.
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Before I start ripping things apart can someone tell me how the temperature gauge in my 72 should read when working properly? It has never worked for me so I have no clue. As of now the needle just stays between 150 and 200 and never moves.
1. When the car is off where should the needle rest?
2. As soon as I start the car should I see any immediate movement at all?
1. When the car is off where should the needle rest?
2. As soon as I start the car should I see any immediate movement at all?
There is no fixed resting point in the temperature gauge. Once power is lost from the actual movement the gauge will (and can float) to where it goes. Once you turn the key on the gauge should go to cold due to the higher ohms reading the sender would be sending out. The ohms on the sender will drop as it heats up.
Lets start this with some simple test...
With the key on go to the sending unit and pull the wire off of it. See where the gauge reads. Then ground that wire out and see where the gauge reads.
With the key on, wire removed, the gauge should look like the picture in the lower left. With the wire grounded out to the car it should look like the one upper left. If the gauge functions in this manner then I'd take a look at the sending unit as your issue. If it doesn't then I'd check the wire from the sender to the gauge for continuity.
Post back.
Willcox
Testing a 68-76 Temperature Gauge -or- What your non working gauge can tell you!
Last edited by Willcox Corvette; Oct 3, 2017 at 05:50 PM.
Thread Starter
Instructor
Joined: Dec 2016
Posts: 218
Likes: 42
From: Hopedale Mass
Mike,
There is no fixed resting point in the temperature gauge. Once power is lost from the actual movement the gauge will (and can float) to where it goes. Once you turn the key on the gauge should go to cold due to the higher ohms reading the sender would be sending out. The ohms on the sender will drop as it heats up.
Lets start this with some simple test...
With the key on go to the sending unit and pull the wire off of it. See where the gauge reads. Then ground that wire out and see where the gauge reads.
With the key on, wire removed, the gauge should look like the picture in the lower left. With the wire grounded out to the car it should look like the one upper left. If the gauge functions in this manner then I'd take a look at the sending unit as your issue. If it doesn't then I'd check the wire from the sender to the gauge for continuity.
Post back.
Willcox
Testing a 68-76 Temperature Gauge -or- What your non working gauge can tell you!
There is no fixed resting point in the temperature gauge. Once power is lost from the actual movement the gauge will (and can float) to where it goes. Once you turn the key on the gauge should go to cold due to the higher ohms reading the sender would be sending out. The ohms on the sender will drop as it heats up.
Lets start this with some simple test...
With the key on go to the sending unit and pull the wire off of it. See where the gauge reads. Then ground that wire out and see where the gauge reads.
With the key on, wire removed, the gauge should look like the picture in the lower left. With the wire grounded out to the car it should look like the one upper left. If the gauge functions in this manner then I'd take a look at the sending unit as your issue. If it doesn't then I'd check the wire from the sender to the gauge for continuity.
Post back.
Willcox
Testing a 68-76 Temperature Gauge -or- What your non working gauge can tell you!
