98 coolant temp sensor to autometer gauge? reading inaccurate!!!
01-22-2009, 05:53 PM
#1
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98 coolant temp sensor to autometer gauge? reading inaccurate!!! does anyone know what resistor to use? for a little more accurate reading...
i am getting a 20 degree lower reading on my autometer gauge than my scan tool. i have not ohmed it out....i am looking for an easy way out
i am getting a 20 degree lower reading on my autometer gauge than my scan tool. i have not ohmed it out....i am looking for an easy way out
01-22-2009, 08:53 PM
#2
You can't do it. Adding resistors will make the gauge read lower.
Not only that but you'd need to put the resistor between the sensor and ground.
Are you using the adapter and short sensor that installs in the rear of the pass side cyl head?
I've got that set up and my autometer gauge reads low too. I've read where people have put the sensor tee'd into the TB bypass hose, if you put it there you will either get a more accurate reading due to better coolant contact. Or you'd have to ground the tee to get the gauge to work, if you know math you could add the resistor to that ground wire.
Heres from their site. Adding resistors won't work, 65 ohms makes the gauge read hotter than 1123 ohms. And with a sender screwed into the block you should have zero ohms there, so no resistor is going to make it read less than zero.
And heres the whole page.
Not only that but you'd need to put the resistor between the sensor and ground.
Are you using the adapter and short sensor that installs in the rear of the pass side cyl head?
I've got that set up and my autometer gauge reads low too. I've read where people have put the sensor tee'd into the TB bypass hose, if you put it there you will either get a more accurate reading due to better coolant contact. Or you'd have to ground the tee to get the gauge to work, if you know math you could add the resistor to that ground wire.
Heres from their site.
Checking the accuracy of a short sweep temperature gauge (one that uses a single terminal sender): This gauge typically has 3 terminals on the rear of the gauge (not including the light connections). It sends a signal out to the sender from the “S” terminal, and it is the senders job to vary this signals resistance to ground. With this said, for a sender and gauge to operate, then sender must be threaded into something that is grounded since the ground path for the sender is actually the sender mounting threads. The gauge itself really is nothing more than a fine tuned & calibrated ohm meter. To check the gauge, you will need a controlled and measurable resistance to ground source. Many shops that deal with automotive electrical repair have what is called a gauge tester, which is really a switchboard with different resistance values. The Auto Meter 100 to 250 degree, short sweep temperature gauge uses a specification of 1123 ohms of resistance to ground to = 100 degrees F, and 65 ohms of resistance to ground to = 250 degrees F. You may contact our Service Department for further specs.
And heres the whole page.
Last edited by 9000th01ss; 01-22-2009 at 09:01 PM.
01-22-2009, 08:59 PM
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You can't do it. Adding resistors will make the gauge read lower.
Not only that but you'd need to put the resistor between the sensor and ground.
Are you using the adapter and short sensor that installs in the rear of the pass side cyl head?
I've got that set up and my autometer gauge reads low too. I've read where people have put the sensor tee'd into the TB bypass hose, if you put it there you will either get a more accurate reading due to better coolant contact. Or you'd have to ground the tee to get the gauge to work, if you know math you could add the resistor to that ground wire.
Heres from their site. And heres the whole page.
Not only that but you'd need to put the resistor between the sensor and ground.
Are you using the adapter and short sensor that installs in the rear of the pass side cyl head?
I've got that set up and my autometer gauge reads low too. I've read where people have put the sensor tee'd into the TB bypass hose, if you put it there you will either get a more accurate reading due to better coolant contact. Or you'd have to ground the tee to get the gauge to work, if you know math you could add the resistor to that ground wire.
Heres from their site. And heres the whole page.
i currently have it wired in the 3rd wire on a 98 3-wire set-up. i guess i just need to learn to add 20.....lol
