Help locate & test temp sending unit
Thread Starter
Instructor
Joined: Oct 2001
Posts: 191
Likes: 1
From: Westport CT
Help locate & test temp sending unit
The temp/water guage on my all stock '70 LT1 barely moves. Even when fully warmed, the needle only moves slightly to about 120-130 degrees
The car and cooling system is well maintained. The heater works.
Where is the temp guage sending unit?
How can i test to see if it's working properly?
If you used a temp sensing gun, where would you aim it? At the main radiator hose?
thans!
The car and cooling system is well maintained. The heater works.
Where is the temp guage sending unit?
How can i test to see if it's working properly?
If you used a temp sensing gun, where would you aim it? At the main radiator hose?
thans!
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
The temp sensor is located in the drivers side head between 1 and 3 cylinder. It should have a green wire with cloth insulation around it. To check the gauge take off the wire and ground it. This should send the gauge to full hot. If it does I would suspect the sending unit in the head.
I check the temp with a gun at various locations. The easiest is at the thermostat. The top hose will be hotter than the bottom hose because the bottom is after the rad. has cooled the water down. The top is the hot engine water going into the rad.
I check the temp with a gun at various locations. The easiest is at the thermostat. The top hose will be hotter than the bottom hose because the bottom is after the rad. has cooled the water down. The top is the hot engine water going into the rad.
Last edited by Gordonm; Aug 23, 2005 at 12:48 PM.
Safety Car
Joined: Dec 1999
Posts: 3,606
Likes: 839
From: PA
Originally Posted by Blue LS1-LT1
Where is the temp guage sending unit?
There are temperature sending units on your Corvette. As Gordon pointed out, the one for the temperature guage is located in the left cylinder head between cylinders 1 and 3 (the other temperature sender is for the TCS and is located in the right cylinder head between 6 and 8).
Externally, the sender should have a shaft type connector without a "head" on the tip (think needle rather than pin). The wiring harness attaches with a white tube shaped connector attached to a green wire covered with a heat resistant black sheath (again, per Gordon's post).
How can i test to see if it's working properly?
Having verified the correct configuration, remove the sender and let it sit inside overnight. Hook it up to an ohmmeter. It should read between 600 and 800 ohms at room temperature... If it fails this test, it needs to be replaced.
The correct replacement temperature sender recently became available in the aftermarket... Give Lectric Limited a call should you need a replacement.
Regards,
Thread Starter
Instructor
Joined: Oct 2001
Posts: 191
Likes: 1
From: Westport CT
Gordon and Stan,
I tested the sending unit by grounding the green wire. I belive it's a faulty sending unit becasue te water temp guage was pinned all the way to the right (hot).
My question concerns the replacement unit's connector. The one in the car, has a head. It looks like a cuff link, or button. The green wire's connector is white plastic and rectangular with a metal blade connector that slides over the button-shaft. Both Zip products, and Paragon sell the needle style. Will that connector still work?
I tested the sending unit by grounding the green wire. I belive it's a faulty sending unit becasue te water temp guage was pinned all the way to the right (hot).
My question concerns the replacement unit's connector. The one in the car, has a head. It looks like a cuff link, or button. The green wire's connector is white plastic and rectangular with a metal blade connector that slides over the button-shaft. Both Zip products, and Paragon sell the needle style. Will that connector still work?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Tough to say. My connecter is black and it is a correct replacement harness. Who knows what connecter has been put on the wire. See if it slides on before putting the new unit in the head. Do a trial fit.
