I have been trying to get my fuel gauge working in my 69. All my gauges were refurbished by Rogers Clocks a few years ago and should be good (?)
Tried the tests I am finding on older posts and the only life I get out of it is when I put 12 V to the bottom and ground the top, it goes below Empty to the point were its 180 degrees from 1/2 full, straight down.
I have it installed in the cluster and it's the last thing I have left to deal with in my automotive electronical NIGHTMARE.
Thanks for any help.
JR

 

12 v to 6 oclock terminal
ground the 9 oclock
the 12 oclock goes to the tank-grounding it should send the needle to empty

 

The tan wire on the back of the gauge goes to the tank unit and the pink one looks like power feed. Can't tell from the print which one goes where on the gauge.

Hook it all up, pull the tan wire off the sender and see where the gauge goes when you turn the key on.
Your description, it almost sounds like the power and ground(sender) leads are reversed

 

Tim, I reversed the pink and brown wires, the gauge moved, I'M encouraged. it went from straight down to empty, I know it has almost exactly a half tank................ ?

 

If you have the tan wire terminal going to ground the gauge should go to empty as I said before....now hook it up to the tank tan wire and see if it goes to half.You do have the resistor across the 6 and 12 oclock terminals dont you ?

 

Roger, been studying on all your old posts

Just to be clear.This doesn't come easy
Key is on, I'm on the back of the gauge cluster and I ground the brown wire connector on the back of the gauge while it's plugged in ? And it should read half.

(sorry to appear so dumb, if I was just a little dumber I wouldn't even know I was dumb)

Yes the resistor is across 6 and 12 and appears to be shiny new.
Thanks for the help

JR

 

Alrighty, I don't think that's what you meant, nothin

JR

 

John,

Stay online, I'll read over this post.

For starters this might help you.

 

Hello again Mr. Wilcox, welcome

JR

 

Ok,

Now we have all the do dads up there.

What I think you should do is test the input wires to the gauge.

The Pink wire is your 12 volt wire and obviously you have 12 volts on this wire. So go to the tan wire at the dash unit and see if you have an ohms reading on this wire.

If you have an ohms reading on this wire I think I would then use the positive wire to verify ground on the cluster. You can do this with your test light and just clip the alligator clip on the cluster and touch the end to the pink wire. Your light should light up.

If all the wires and the ground test fine then you have a gauge problem.

As shown above, there is a 90 ohm resistor on the back of the gauge. Test across this resistor and see if you get 90 ohm’s resistance. If you don’t then you might try replacing this resistor.

If the ohms wire at the dash unit is without ohms, the gauge would peg full. If you have a dash unit without a ground the gauge will stay pretty much put and not move with power and ohms. If the power is missing from the gauge it will pretty much respond like above on the missing dash ground. Going to 6 o’clock is a sign the gauge is wired wrong.

I have my tester here right now. If you are still lost, I can hook a gauge up and see what will cause it to act this way.

If you don’t mind me asking. . . How did you get ground to the top wire? The ground on this gauge is supplied thru the 9 o’clock stud on the back of the gauge and it is created by the nut that holds down the stud to the housing.

I really think you need to get the two wires in the picture above the way they belong, signal on top, 12 volts to the bottom and ground on the gauge. Then tell me what the gauge does. Or did I miss this. . . Let me read more. . .

Willcox

 

Ok, while you were reading I ran out to the garage to compare the schematic to the back of the gauge, (they're twins) I noticed nothing going to the ground connector and a black (very light gauge) wire jumping from the pink 12V connector over to the seatbelt warning copper thingy. Is this my problem ?

 

Wilcox has this under control but I would like to add the cluster gets its ground through the center black wire on the 3 wire temperature gauge plug. So if you dont have the temperature gauge plug installed you will need a temporary ground for the cluster to make the fuel gauge work.

 

Not sure, but no I don't think this is your problem. The pink wire is a power wire so this would not change anything as long as you have 12 volts on the pink wire.

Can you test the wires and tell me what is on which wire? You really need to do this. Test the pink for voltage, test the tan for ohms and test the cluster to see if you have a ground. This will tell me more than anything you can do! Post again. Without a ground at the cluster the needle would not be responsive at all. It might float a little but nothing of importance. I really need to know what is on what wire! I think everyone watching would like to know.

This gauge is not hard to figure out but without knowing what is on what wire it makes it hard.

What one poster was telling you is that if you have the correct wires to the gauge and everything is perfect! If you remove the signal wire the sending unit the dash unit will peg full! Regardless of what you have in the tank. . . It will peg due to the lack of signal.


Willcox

 

Man, I don't know how dumb I am anymore

I went and put a ground wire on the ground terminal and then reached around and put it on the wrong battery post.

Temp gauge is now at 6:00 and I have no dash lights or other gauges except the clock.

I hope it's just fuses but I will have to get some tomorrow and then hopefully just go through the steps you've got above.
As I should have done anyways, I know, I know.

Thanks guys............I'm gonna have a Crown-n -Coke now PMO

JR

 

Also Ernie if he has 1/2 tank = 45 ohms on the tan wire
12 volts on the pink
NO ground to the cluster
The needle will go to empty.
Once you ground the cluster the needle should go to 1/2

 

 

Roger,

On the tester when I removed the ground wire to the dash unit ground powered up the gauge moved only a little but didn't move to empty. Funny but it moves some toward empty but only a little bit. It might be the gauge causing this, I'll hook it up tomorrow night. . . I'm tired!

I'm going to look over the threads and then pack it in!

Willcox

 

John,

Direction 1. . . Stop hooking wires up!

Now test the wires tomorrow and please don't do this tonight with the crown and coke!

Direction 2: Post tomorrow what each of the two wires on the connector have and please it's real easy to test the ground of the cluster as described above!

Not testy. . . No soup for you!

Willcox

 

What I was trying to say was if you have everything hooked up like normal and just remove the ground like you did in your video above the gauge will go to empty. I think he might be missing the cluster ground.

 

I have this terrible habit of reading directions last, Momma must be right......eventually I will catch on.
( 53 now, wonder when ?)

Thanks Guys, will post tomorrow

JR