C3 temperature sender
Thread Starter
Racer
Joined: Sep 2017
Posts: 338
Likes: 56
C3 temperature sender
Hi again. still working on temp. gauge. I have been trying to get an accurate reading on my temperature gauge, 69 SB and not original gauge or sending unit. I am reading about 40 ohms. high according to the Willcox numbers for the 180 degree temp ( first mark on gauge). Tested a few different sending units and they were consistent but the ohms were all high and would give a false low temperature. Verified with an I.R. gun. This seems to be the case for aftermarket senders and gauges.
What I would like to know or explained to me is why the adjustable resistor that is available not able to be hooked up to a replacement gauge so that the ohms between the sending unit and gauge can't be adjusted for what the ohms should be that the gauge needs to receive for an accurate reading. Hope this makes sense.The fact that their seems to be no way to get an accurate reading seems hard to believe. Thanks and take care.
What I would like to know or explained to me is why the adjustable resistor that is available not able to be hooked up to a replacement gauge so that the ohms between the sending unit and gauge can't be adjusted for what the ohms should be that the gauge needs to receive for an accurate reading. Hope this makes sense.The fact that their seems to be no way to get an accurate reading seems hard to believe. Thanks and take care.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Hi again. still working on temp. gauge. I have been trying to get an accurate reading on my temperature gauge, 69 SB and not original gauge or sending unit. I am reading about 40 ohms. high according to the Willcox numbers for the 180 degree temp ( first mark on gauge). Tested a few different sending units and they were consistent but the ohms were all high and would give a false low temperature. Verified with an I.R. gun. This seems to be the case for aftermarket senders and gauges.
What I would like to know or explained to me is why the adjustable resistor that is available not able to be hooked up to a replacement gauge so that the ohms between the sending unit and gauge can't be adjusted for what the ohms should be that the gauge needs to receive for an accurate reading. Hope this makes sense.The fact that their seems to be no way to get an accurate reading seems hard to believe. Thanks and take care.
What I would like to know or explained to me is why the adjustable resistor that is available not able to be hooked up to a replacement gauge so that the ohms between the sending unit and gauge can't be adjusted for what the ohms should be that the gauge needs to receive for an accurate reading. Hope this makes sense.The fact that their seems to be no way to get an accurate reading seems hard to believe. Thanks and take care.
Okay, on the original gauges the resistor is external, on the reproduction gauges, when you install them they come with a plastic spacer and the resistance is on the inside of the gauge. So if you add our adjustable resistor to the gauge you'll double up on the resistance and the gauge will not function. Why they made the imported reproduction gauges with the resistance on the inside... I have no clue... When the adjustable resistor is installed on a factory gauge you are making a linear change to a non linear gauge, but when you already have resistance in the gauge this is pretty much impossible. I suppose in the future I'll take a look at a possible solution but for now the resistors fly off the shelf as fast as we can make them.
Willcox
Last edited by Willcox Corvette; Aug 11, 2018 at 06:51 PM.
Thread Starter
Racer
Joined: Sep 2017
Posts: 338
Likes: 56
Wow.. this is the easiest answer I've had all week...
Okay, on the original gauges the resistor is external, on the reproduction gauges, when you install them they come with a plastic spacer and the resistance is on the inside of the gauge. So if you add our adjustable resistor to the gauge you'll double up on the resistance and the gauge will not function. Why they made the imported reproduction gauges with the resistance on the inside... I have no clue... When the adjustable resistor is installed on a factory gauge you are making a linear change to a non linear gauge, but when you already have resistance in the gauge this is pretty much impossible. I suppose in the future I'll take a look at a possible solution but for now the resistors fly off the shelf as fast as we can make them.
Willcox
Okay, on the original gauges the resistor is external, on the reproduction gauges, when you install them they come with a plastic spacer and the resistance is on the inside of the gauge. So if you add our adjustable resistor to the gauge you'll double up on the resistance and the gauge will not function. Why they made the imported reproduction gauges with the resistance on the inside... I have no clue... When the adjustable resistor is installed on a factory gauge you are making a linear change to a non linear gauge, but when you already have resistance in the gauge this is pretty much impossible. I suppose in the future I'll take a look at a possible solution but for now the resistors fly off the shelf as fast as we can make them.
Willcox
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Why do you care that the temp gauge is not at all accurate at "low temps"? There is only one reason to look at the temp gauge: to see if the engine is operating at its 'normal' temperature (what you usually see when the engine is fully warmed up). If it is at normal position, all is good. If the temp is above normal, there's a problem.
I don't know of anyone who watches the temp gauge when the car is cold. When testing for a cooling system issue, one could watch the gauges transition from 'cold' to 'hot'; but I've never considered the temp gauge to be an accurate device. It's merely a tool used to observe for unexpected temp changes.
I don't know of anyone who watches the temp gauge when the car is cold. When testing for a cooling system issue, one could watch the gauges transition from 'cold' to 'hot'; but I've never considered the temp gauge to be an accurate device. It's merely a tool used to observe for unexpected temp changes.
Last edited by 7T1vette; Aug 12, 2018 at 06:43 AM.
