Temp gage not working
06-20-2007, 03:18 PM
#1
Drifting
Thread Starter
Temp gage not working
The shop manual doesn't give any type of testing for a faulty temp gage/sensor. I am hoping it's the sensor near the Alternator. If I pull the green wire and use a volt meter and I got power to the sensor, I suppose my only choice is a new sensor or a new gage in the center cluster?
06-20-2007, 03:22 PM
#2
Le Mans Master
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That is the correct sensor. It is a ground sensor, the fact that there is power to it indicates that you have power thru the gauge so its not a fuse or circuit problem. Ground the wire and see what the gauge does, it should peg High, if not, the gauge has a problem and will require further inquiry.
While your under the hood measure the resistance from the pin on the sensor to ground.
While your under the hood measure the resistance from the pin on the sensor to ground.
06-20-2007, 03:31 PM
#3
Drifting
Thread Starter
Will do once I get home tonight and I'll let you know. Man I was hoping NOT to have to open th e center gage cluster up again but also found the spot light was not working last night either 
(That's the one that shines down onto the center console from above the center gage cluster.
(That's the one that shines down onto the center console from above the center gage cluster.
06-20-2007, 04:19 PM
#6
Instructor
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old gauges go bad, i bought an entire center cluster of gauges off ebay (I had 2 that were broken) so now i have some backups, they are each separate gauges and can be replaced independently.
06-22-2007, 10:47 AM
#7
Drifting
Thread Starter
That's good to know - cause I had 12volts on the sensor. Not sure what's at the gage though. I still have to check the gage to see if the needle will move if I ground the sensor wire. If that doesn't work, the sensor is about $46.00 and the gage is $60.00 from Mid-America. Which should I start with? How often does the actual sensor go out?
06-22-2007, 10:55 AM
#8
Le Mans Master
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The 12v at the sensor wire comes from the 12v at the gauge, so youknow you have good power at the gauge. Could be either sensor or gauge, could even be the ground at the gauge
06-22-2007, 02:17 PM
#9
Le Mans Master
Lectric Limted for the sensor. www.lectriclimited.com. $25 and they are they only place that has sensors with the correct resistance range.
Last edited by SteveG75; 06-22-2007 at 02:19 PM.
06-22-2007, 02:56 PM
#10
Drifting
Thread Starter
Is each individual gage grounded seperately? All other gages in the cluster work. On the back of the gages you have the circuit overlay and the plug harness makes contack with that. I have not removed that from the back of the gage cluster cause I was scared I'd mess it up. How are the gages grounded?
06-22-2007, 03:09 PM
#11
Drifting
Thread Starter
Lectric Limted for the sensor. www.lectriclimited.com. $25 and they are they only place that has sensors with the correct resistance range.
06-22-2007, 03:19 PM
#12
Le Mans Master
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Is each individual gage grounded seperately? All other gages in the cluster work. On the back of the gages you have the circuit overlay and the plug harness makes contack with that. I have not removed that from the back of the gage cluster cause I was scared I'd mess it up. How are the gages grounded?
06-22-2007, 03:48 PM
#13
Drifting
Thread Starter
Danny check out that web-link above cool site. Lots of electrical hard to find parts.
06-22-2007, 05:54 PM
#15
My gauge reads low and has since I got the car - maybe the sender was replaced as mentioned on the website. Is there a way to calibrate our temp gauges, or should I order up a new sender?
06-22-2007, 09:59 PM
#16
Race Director
Have you done the standard book test? Remove wire from sender and gage should go to full cold-ground wire gage should go full hot.If it doesnt do this you have a problem in the wiring or gage to fix first.If you want a calibrating standard to check your gage with you can put an 68 ohm resistor between the sender wire and ground.The gage should read 215-220.
06-25-2007, 10:06 AM
#17
Thanks, I'll try the resistor! I grounded the wire and it pegs, so the gauge works. I also used an infared thermometer, and the gauge reads about 150 when the intake near the sender is actually 190. If the gauge is off (and not the sender) is there a way to adjust that?
06-25-2007, 10:12 AM
#18
Le Mans Master
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Sounds like the calibration resistor on the back of the gauge is original and the sender is aftermarket. When I get to putting my dash back in I may turn my attention to a method to truely calibrate the gauges, got to think about that a bit.
06-25-2007, 10:25 AM
#19
Race Director
That should be interesting.Of course adding resistance in the sender wire just makes the gage read colder but I wonder what happens when you very the resistor on the back of the gage.That resistor is between the gage and ground.Hmmm if I get time I will try changing that resistor and see what it does.I have about 4 diff. colors.
06-25-2007, 10:39 AM
#20
Le Mans Master
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Roger, that would be the key. Its a shunt I think, different values for different temp senders. The problem is each gauge and each sender has a tolerence, I don't know what the window is on the components. But making the calibration resistor a variable, or wrapping a custom based on a measurement might be the way to go. One of the first cars I did was a 67 mustang, I re wound all the gauges so thay they were dead on, when the needle hit the center mark on the E you better be looking AT a gas pump