New temperature sensor same problem.
Thread Starter
Racer
Joined: Jun 2015
Posts: 250
Likes: 25
New temperature sensor same problem.
Replaced the temperature sensor with a TU5 sensor and the same results. Temperature gauge needle peeks out at about 135 degrees. When I ground out the dark green wire needle goes full scale deflection toward hot. I traced the dark green wire (has a black protective sleeve over it) and it seems to go into a bundle of wires. I traced those wires to one of 2 bulk head plugins They are somewhat under the power brake booster. Would disconnecting the one that is farther from the drivers fender and apply some die-electric grease do any good. If so how do you disconnect the bulkhead plugin. Non-Contact Infrared Thermometer on the thermostat housing I get a reading of 190 degrees.
Last edited by cblankin; Oct 11, 2015 at 05:56 PM.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,925
From: Washington Michigan
Replaced the temperature sensor with a TU5 sensor and the same results. Temperature gauge needle peeks out at about 135 degrees. When I ground out the dark green wire needle goes full scale deflection. I traced the dark green wire (has a black protective sleeve over it) and it seems to go into a bundle of wires. I traced those wires to one of 2 bulk head plugins They are somewhat under the power brake booster. Would disconnecting the one that is farther from the drivers fender and apply some die-electric grease do any good. If so how do you disconnect the bulkhead plugin. Non-Contact Infrared Thermometer on the thermostat housing I get a reading of 190 degrees.
Team Owner
Joined: Jul 2006
Posts: 22,162
Likes: 4,171
From: Kannapolis NC
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
You have proven the gauge is working but is it working correctly? You can figure this out pretty easy. If you have a potentiometer use it as your source ohms and test the gauge.
If you don't have one... an old cheat trick is to use a flasher. A turn signal flasher has around 50-55 ohms resistance so if you have one laying around whip out your ohms meter and take a reading to see. Then insert this as your sender and see where the temperature gauge goes. Once you know the input you can match it up to the chart below and see if the gauge is working properly. If you want to raise the resistance just put another flasher in a series.... and you'll be around 100-110.
50-55 ohms on a 65 gauge should put it past 240. On a 66-67 gauge it should take it to the 250 mark. If you double the flashers up though you'd be around 100-110 which would be somewhere between 180 and the second mark on the 65 gauge face and right at the first mark on a 66.
If you find the gauge to be reading correctly then punt.. get the adjustable resistor and you can match any gauge to any sender for 1965-1967. (sorry 63-4 guys, we don't have a solution for you yet).
https://willcoxcorvette.com/corvette...resistor-65-67
65-67
If you don't have one... an old cheat trick is to use a flasher. A turn signal flasher has around 50-55 ohms resistance so if you have one laying around whip out your ohms meter and take a reading to see. Then insert this as your sender and see where the temperature gauge goes. Once you know the input you can match it up to the chart below and see if the gauge is working properly. If you want to raise the resistance just put another flasher in a series.... and you'll be around 100-110.
50-55 ohms on a 65 gauge should put it past 240. On a 66-67 gauge it should take it to the 250 mark. If you double the flashers up though you'd be around 100-110 which would be somewhere between 180 and the second mark on the 65 gauge face and right at the first mark on a 66.
If you find the gauge to be reading correctly then punt.. get the adjustable resistor and you can match any gauge to any sender for 1965-1967. (sorry 63-4 guys, we don't have a solution for you yet).
https://willcoxcorvette.com/corvette...resistor-65-67
65-67
Racer
Joined: Jun 2013
Posts: 337
Likes: 27
From: Fremont CA
Replaced the temperature sensor with a TU5 sensor and the same results. Temperature gauge needle peeks out at about 135 degrees. When I ground out the dark green wire needle goes full scale deflection. I traced the dark green wire (has a black protective sleeve over it) and it seems to go into a bundle of wires. I traced those wires to one of 2 bulk head plugins They are somewhat under the power brake booster. Would disconnecting the one that is farther from the drivers fender and apply some die-electric grease do any good. If so how do you disconnect the bulkhead plugin. Non-Contact Infrared Thermometer on the thermostat housing I get a reading of 190 degrees.
Warm up your car test with IR temp gun - do some research regarding what it the correct resistance (sensor output to ground) and get/borrow a Ohm test meter. Most likely something is not grounding correctly with the sensor. I read having too much Teflon on the treads of the sensor could be something to review. Use only enough Teflon to seal the top of the senor's mounting threads and not all of the threads.
Irwin
Thread Starter
Racer
Joined: Jun 2015
Posts: 250
Likes: 25
Can't seem to fix the problem
Made sure the threads in the intake where the coolant temperature sensor screws in were clear and did not use any Teflon tape or thread sealant and still temperature will only go to about 135 degrees on the gauge My Non-Contact Infrared Thermometer pointed at the thermostat housing I get a reading of 185 degrees. The thermostat is fully opened. When I ground out the wire going to the sensor the gauge needle deflects full scale to the right. After the engine cooled I opened the coolant recovery tank and about 8-10 oz puked out. How do I replace what I lost?
Racer
Joined: Jun 2013
Posts: 337
Likes: 27
From: Fremont CA
Made sure the threads in the intake where the coolant temperature sensor screws in were clear and did not use any Teflon tape or thread sealant and still temperature will only go to about 135 degrees on the gauge My Non-Contact Infrared Thermometer pointed at the thermostat housing I get a reading of 185 degrees. The thermostat is fully opened. When I ground out the wire going to the sensor the gauge needle deflects full scale to the right. After the engine cooled I opened the coolant recovery tank and about 8-10 oz puked out. How do I replace what I lost?
Race Director
Joined: Apr 2005
Posts: 11,260
Likes: 2,129
From: Bowling Green, Kentucky
https://www.corvetteforum.com/forums...ding-unit.html Post #4.
Here is a thread from someone with a similar problem a few weeks ago, and our forum recommendations. From the archives: https://www.corvetteforum.com/forums...r-fitment.html
Larry
Last edited by Powershift; Oct 11, 2015 at 07:08 PM.
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