Gauge Issues
01-03-2018, 04:54 PM
#21
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
I have another thought/question. The Wilcox troubleshooting says that if the resistor is blown the gauge will read a little above 1/4 tank. It actually says it will only function up to that mark. So does that mean that if it is a blown resistor the gauge will operate between E for empty and a little above 1/4 for full? If so, that would make sense for me since the tank is about 1/2 full and the gauge reads about 1/8.
01-05-2018, 06:18 PM
#22
Instructor
Thread Starter
Just because the sender output test okay in a bench test doesn't mean its grounded properly or there isn't a wire issue...
So.. pull the ohms wire from the car and ground it with the key on, see where the dash unit goes... then let it free hang without touching anything and see where the gauge goes... if it pegs when not touching and goes to empty when grounded, the problem is in the rear of the car.
It's that simple... If you can eliminate the dash unit and all the wires from the rear of the sender forward... you're that much closer to solving the issue.
Willcox
So.. pull the ohms wire from the car and ground it with the key on, see where the dash unit goes... then let it free hang without touching anything and see where the gauge goes... if it pegs when not touching and goes to empty when grounded, the problem is in the rear of the car.
It's that simple... If you can eliminate the dash unit and all the wires from the rear of the sender forward... you're that much closer to solving the issue.
Willcox
Last edited by Lark327; 01-05-2018 at 06:19 PM.
01-10-2018, 09:26 PM
#23
Instructor
Thread Starter
Just because the sender output test okay in a bench test doesn't mean its grounded properly or there isn't a wire issue...
So.. pull the ohms wire from the car and ground it with the key on, see where the dash unit goes... then let it free hang without touching anything and see where the gauge goes... if it pegs when not touching and goes to empty when grounded, the problem is in the rear of the car.
It's that simple... If you can eliminate the dash unit and all the wires from the rear of the sender forward... you're that much closer to solving the issue.
Willcox
So.. pull the ohms wire from the car and ground it with the key on, see where the dash unit goes... then let it free hang without touching anything and see where the gauge goes... if it pegs when not touching and goes to empty when grounded, the problem is in the rear of the car.
It's that simple... If you can eliminate the dash unit and all the wires from the rear of the sender forward... you're that much closer to solving the issue.
Willcox
01-11-2018, 04:08 PM
#24
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Did you read this? http://repairs.willcoxcorvette.com/w...it-testing.pdf
If you tested the resistor on the gauge that's not your problem. The resistor will test around 47 ohms installed, off the gauge it should read around 90-94 ohms.
Willcox
If you tested the resistor on the gauge that's not your problem. The resistor will test around 47 ohms installed, off the gauge it should read around 90-94 ohms.
Willcox
01-12-2018, 02:44 PM
#25
Instructor
Thread Starter
OK Willcox, I have some more info. The tan wire on the harness at the gauge has ohms of around 40. This is the same as at the tank sender and is close to the estimated amount of gas in the tank on a scale of 0-90. I followed your diagnostics and with 12v to number 2 and ground to number 1 terminal of the gauge it goes to empty. moving the ground wire from number 1 to number 5, the gauge goes to the 3 oclock position, both as it should.
I tested the resistor on the gauge when I got a 43.4 reading across the terminals. When I removed the resistor I got a reading of 84. There is a dark, almost oily looking spot in the center of the resistor.
I should mention that I did not check the voltage at the fuse block because the way the car is parked I cant reach it. When I checked power on the pink wire at the gauge connector, I got a reading of 11.28v. A check directly across the battery terminals gave me a reading of 12.01v. The battery may be a little low because I haven't been driving it. Is this voltage drop normal? If not, would it cause the gauge to read improperly? The tank appears to be somewhere between 1/3 to 1/2 full. The reading I get on the gauge now is about 1/4. In the past when the gas tank was 3/4 full I got a reading a little bit above 1/4. The gauge has always moved within that range. Once when driving, it shot up to the 3 o'clock position Does any of this make sense? I should also note that this is a 60,000 mile car and the gauges, terminals etc are pristine. Not a speck of corrosion anywhere.
Also I don't know if it matters but the way the wires on the connector line up to the gauge are opposite of what is embossed in the rear of the gauge cluster. In other words the pink wire is on where it says tan and tan is on where it says pink. Would this matter? It looks to have always been this way as the wires have taken a set and it would be difficult at best to plug it in the opposite way.
Did I tell you I HATE electrical issues. Thanks
I tested the resistor on the gauge when I got a 43.4 reading across the terminals. When I removed the resistor I got a reading of 84. There is a dark, almost oily looking spot in the center of the resistor.
I should mention that I did not check the voltage at the fuse block because the way the car is parked I cant reach it. When I checked power on the pink wire at the gauge connector, I got a reading of 11.28v. A check directly across the battery terminals gave me a reading of 12.01v. The battery may be a little low because I haven't been driving it. Is this voltage drop normal? If not, would it cause the gauge to read improperly? The tank appears to be somewhere between 1/3 to 1/2 full. The reading I get on the gauge now is about 1/4. In the past when the gas tank was 3/4 full I got a reading a little bit above 1/4. The gauge has always moved within that range. Once when driving, it shot up to the 3 o'clock position Does any of this make sense? I should also note that this is a 60,000 mile car and the gauges, terminals etc are pristine. Not a speck of corrosion anywhere.
Also I don't know if it matters but the way the wires on the connector line up to the gauge are opposite of what is embossed in the rear of the gauge cluster. In other words the pink wire is on where it says tan and tan is on where it says pink. Would this matter? It looks to have always been this way as the wires have taken a set and it would be difficult at best to plug it in the opposite way.
Did I tell you I HATE electrical issues. Thanks
03-14-2018, 01:16 PM
#26
Instructor
Thread Starter
Just because the sender output test okay in a bench test doesn't mean its grounded properly or there isn't a wire issue...
So.. pull the ohms wire from the car and ground it with the key on, see where the dash unit goes... then let it free hang without touching anything and see where the gauge goes... if it pegs when not touching and goes to empty when grounded, the problem is in the rear of the car.
It's that simple... If you can eliminate the dash unit and all the wires from the rear of the sender forward... you're that much closer to solving the issue.
Willcox
So.. pull the ohms wire from the car and ground it with the key on, see where the dash unit goes... then let it free hang without touching anything and see where the gauge goes... if it pegs when not touching and goes to empty when grounded, the problem is in the rear of the car.
It's that simple... If you can eliminate the dash unit and all the wires from the rear of the sender forward... you're that much closer to solving the issue.
Willcox
03-14-2018, 05:43 PM
#27
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
