My gauges look fine from the rear, no damage or wear, but they don't work. The speedometer works fine, but that's mechanical. I put a new gas tank, fuel sender unit, and wire from the sender unit to the harness in, and the gauge still doesn't register. My shop said to look at a ground wire on the back of the gauge cluster that isn't connected properly. I looked for one, but didn't have any success. I was hoping someone here might know what I need to do to get this working properly. Here are a few pictures of the rear of the gauge cluster:
Two grounds involved. One on the back of the cluster, just a regular sheet metal screw - that has a thin metal rod with a loops on the end that runs to the center top instrument cluster screw on the dashboard. Don't see the thin rod in your photo.
You can compensate with a piece of wire to one of the rear cluster screws grounded to the car.
Then there is the ground wire for the fuel sender itself under the car in front of the gas tank where the passenger side gas tank strap attaches to the trunk floor.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
Two grounds involved. One on the back of the cluster, just a regular sheet metal screw - that has a thin metal rod with a loops on the end that runs to the center top instrument cluster screw on the dashboard. Don't see the thin rod in your photo.
You can compensate with a piece of wire to one of the rear cluster screws grounded to the car.
Bingo. Take it off and clean up the mounting locations to make sure you are getting a clean ground.
I backed mine up with a wire to insure a good ground. One of those items I want to take out to fix something as infrequently as possible.
You also have to insure that the metal clip that center screw goes into is also clean and the screw is tight.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
Get some jumpers (Radio Shack has a bundle for less than $10) and get the assembly working before you put is back. You will be able to divide the problem and determine where the problem is.
Last photo - the metal band needs to go between the screw and the bare metal rear can.
If you have an eletrical multi-tester - check for continuity from one end of the metal band to the other.
If you have continuity - could be a new problem with the gauge. Do the dash lights work properly - they use the same dash ground.
Did you ground the fuel tank sender at the back of the car?
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
I think you found it. According to the '67 wiring diagram, that connector should have a brown wire and beige or light pink wire going in and both going out. The beige or light pink is for the fuel sender. It comes into the bottom of the trunk through a rubber plug (if memory serves).
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
1) The other wire in the trunk is for the license plate light.
2) I would go ahead and change out all the instrument cluster bulbs for new ones and retest. Good time to put all new bulbs in there while you have it out. And you will have eliminated burned out bulbs from the equation.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
1) The other wire in the trunk is for the license plate light.
2) I would go ahead and change out all the instrument cluster bulbs for new ones and retest. Good time to put all new bulbs in there while you have it out. And you will have eliminated burned out bulbs from the equation.
This gets odder and odder. I was taking the gauges in and out, and one some attempts, all of the lights in the gauges light up, and when I turned the light switch on the dash they would go on and some locations, and off at others, flickering almost. It was strange. Took the light switch out and brushed off the connections, no dice. I havn't figured out what is making them come on sometimes and off others.
Ah, there is a reostat built into the headlight switch. It controls the brightness of the dash lights and at the extreme bright should turn on the overhead dome light.
Anyway - make sure it's not turned all the way down.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI